Hairball of the Pet Avengers (Marvel Comics) frowning

Niels the cat aka Hairball

Power Level:
Game system: DC Heroes Role-Playing Game


Niels appears in 1988, as an ordinary if troublesome housecat in Marvel’s Speedball comic book. He later gains super-powers akin to Speedball’s.

Starting in 2009, Niels becomes portrayed as a sapient  being in comic books about super-animals, mostly aimed at children (the Pet Avengers).

This entry uses “it” when Niels is portrayed as an animal, and “he” when he’s portrayed as a sapient being.

Warning – there be S P O I L E R S about the Pet Avengers Limited Series therein.



  • Real Name: Niels.
  • Former Aliases: P-Cat the Penitent Puss (allegedly).
  • Other Aliases: “Here kitty kitty”, “Stupid cat”, “Danged cat”, “Dumb cat”, Niels the Bouncing Cat, “Pesky pussy”.
  • Marital Status: N.A..
  • Known Relatives: None.
  • Group Affiliation: Pet Avengers.
  • Base Of Operations: Originally Springdale, Connecticut ; later Queens, New York City, New York.
  • Height: 12” at the shoulder Weight: 10 lbs.
  • Eyes: Black on yellow Hair: Burnt orange fur.

Powers and Abilities

Niels is pretty good at cat stuff such as climbing on things, prowling around, grooming itself, chasing things, demanding attention, demanding food, demanding that the door be opened, demanding that the door be closed, etc.. It has a knack for evading pursuit, and good reflexes.

Niels has often been described as being more slippery than a greased pig. Yet it’s also very good at getting underfoot. Despite weighing but 10lbs. Niels is surprisingly good at tripping people, even though it usually doesn’t really mean it.


The kinetic cat

As Hairball, Niels has powers that seem broadly identical to those of Robbie Baldwin as Speedball. That is, he can absorb kinetic energy and release it. He is practically immune to impacts, and can harness kinetic energy to :

  • Launch himself in the air.
  • Achieve bursts of speed.
  • Throw concussive, multicoloured volleys of kinetic energy spheres from his paws. These aren’t going to kill anyone, but can knock an adult human down, especially of the target is caught by surprise.

Though his mastery of his kinetic abilities isn’t comparable to Speedball’s, Niels could leap on top of a two-story building from day one. This is done by spending accumulated kinetic energy from running and jumping around. Like Speedball, Niels can ricochet off surfaces at high speeds and with good precision, and is bulletproof.

Robby Baldwin chases Niels the cat

Between his small size, alacrity and feline agility, Hairball is nigh-impossible to hit or catch. He even once performed something that looked like a running backward somersault, though it was presumably not quite on purpose. He was likely trying to land on his feet after bouncing from a wall.

Freak occurrences where Niels gets hit do occur from time to time, though, such as against the Harlequin Hitman.

Other assets and weaknesses

Due to his poor perception of both depth and immobile objects, Niels has a hard time doing aerobatics. For instance he’s very bad at spotting the ledges of buildings at high speed. On the other hand the resultant falls do not hurt him and he’ll just bounce on.

Even though he was an employee at a research lab for years, Niels doesn’t appear to have picked up any scientific or technical knowledge.

Hairball was briefly the holder of the fabled Soul Gem (the green Infinity Gem). This is the very artefact that once adorned Adam Warlock’s brow.

Animal talk

In the genre the Pet Avengers operate in, all animals are sapient and can talk with each other, even across species. The only people not understanding animals are humans and related species, though animals still try to talk at them from time to time.

But it is considered normal for, say, a lhasa apso dog  to talk to an hippopotamus.

However, animals tend to have a one-track mind and limited intellectual resources. In game terms there are usually penalties to convince one to change its mind, and most animals do not have strong enough social skills to overcome these penalties.

Note that Lockheed, despite being a fully sapient alien, can talk with animals without hindrance. He presumably uses the same empathic powers he uses to understand humans, and taught himself the language from there.

Curiously, humans turned into animals (say, through magical means) can often communicate with animals, but can no longer form human languages.

Frog Thor is thus an important Pet Avenger. Since he can fluently communicate both in English and with animals, he serves as the face of the team. He’s also the one with people skills.


Niels was first seen as the feline-in-residence at Hammond Research Center, Springdale, tri-states area. Nominally the property of leading researcher Dr. Benson, Niels met with teenager Robbie Baldwin when the kid was hired as a gopher.

Mere hours after they met, both Robbie and Niels were accidentally irradiated by an experiment to access another dimension . They both developed kinetic powers and Baldwin would soon become Speedball, the Masked Marvel.

Though Benson determined that the experiment had irradiated a living being, he thought that only the cat had been hit. Tests determined that Niels was now surrounded by a sort of invisible energy cushion, but capturing Niels had been difficult and it soon escaped.

Run Niels run

Dr. Benson sent Robbie to catch the cat, which proved impossible. The lab’s handyman, Claude, joined the hunt, but none could lay hand on the deft and kinetically-charged kitty. Which was a good thing, since Claude looked pretty threatening with that hammer in hand.

Hairball running amidst bubbles

As weeks went by, Niels was occasionally spotted by Springdale residents, usually after falling off a building and chaotically bouncing away.

Early during Speedball’s career, a masked murderer called the Two-Legged Rat became a serial killer of Springdale’s cats. The Rat was foiled when Niels pounced on him as a he was aiming with his rifle, ruining his shot. Speedball, who had been chasing Niels, then ran into the Rat, who was forced to flee.

In 1989, Niels was spotted by humanoid space house cats in a flying saucer. They thought that Niels was some kind of super-powered mutant and tried to rescue him from the ’monster‘ chasing him – Speedball. Baldwin had been carrying catnip in a futile attempt to lure Niels in, and used it to distract the space cats and escape.

The bouncing cat strikes again

Speedball continued to chase Niels for months. His reasoning was that having Benson study Niels was the only way to learn about his powers without exposing his secret identity. However, he never succeeded.

The cat seemed to like Baldwin. It occasionally kept him company after it saw the teenager emit kinetic “bubbles” like his own. Eventually Robbie just gave up, which of course prompted Niels to want Robbie to resume “playing” at chasing it.

Hairball scowling

When the (Mad) Thinker developed a benign interest in the New Warriors, he tracked Speedball down thanks to persistent rumours of a bouncing cat and a bouncing guy in Springdale. The Thinker easily caught Niels, but released it after studying its powers, with the only damage done being to Niels’s pride.

Villainous schemes are afoot

When Baldwin left for New York City for a summer, most of the peculiar super-villains in Springdale (including the Two-Legged Rat) worked together to catch Niels. They eventually succeeded.

Clyde, the man allegedly behind many of the absurd local villains, also captured Speedball when he came back. Clyde was plotting to steal Niels’s and Speedball’s powers to become the villain Rebound.

Niels saved the day. Through helplessly strapped to an operating slab, it had been struggling with a hairball for hours. When the cat managed to expectorate the hairball, it was imbued with a considerable kinetic charge. The hairball and a hectic Niels wrecked Clyde’s lab and took out most of the villains by bouncing everywhere at high speeds.

This triumph (and having finally gotten rid of the hairball) changed Niels’s disposition for the better. It became Robbie’s pet. Dr. Benson gave the cat to his former gopher, who responded by buying a hair brush for the puss.

Robbie soon brought Niels with him to New York City, though the cat hated the kitty carrier and blew a hole through it whilst on the train. The bouncing cat established its quarters in Baldwin’s apartment in Queens. There occasionally was trouble, such as the Guardians of the Galaxy attacking the New Warriors there.

Holding out for a hero

After the Stamford catastrophe that ultimately led to the Civil War, the traumatised Speedball became Penance, a self-torturing obsessive with severe psychological issues.

During that time there were silly rumours that Niels had become P-Cat, the Penitent Puss, wearing spiked armour and spiked collar just like Penance. There were even photos, though I’d assume those were just Photoshop™ jokes circulating on the Internet.

With his owner going insane, ending up in prison and manipulated into government service Niels was apparently left to fend for himself in Queens. These were not happy times, especially after he started running into a neighbourhood puppy called Ms. Lion – actually a male, and not terribly leonine.

This is a job for… Hairball !

The calamitously cretinous canine wanted to become Niels’ friend, and thought that the cat’s super-powers were the coolest thing ever. Perhaps to maintain his feline pride despite the hardship, Niels adopted a super-hero name, calling himself Hairball.

Hairball was later recruited by the Pet Avengers — Lockjaw, Redwing, Frog Thor, Lockheed, Zabu and — unfortunately — Ms. Lion. These stalwart animals went on a grand quest to recover the Infinity Gems before Thanos could find them and trigger yet another massive crossover event.

As part of this worthy endeavour, Lockjaw, the leader of the group, used the Mind Gem to create a psychic communication link between our heroes.

Hairball surrounded by kinetic energy bubbles

The exciting quest of the Pet Avengers led them to find the last Gem in the White House, where they also temporarily recruited Bo, the Presidential puppy. Thanos found them there and killed Ms. Lion, but Hairball instinctively used the power of the Soul Gem to resurrect him, and heal Zabu who had been blasted by the mad titan.

Armed with the entire set of Infinity Gems, Lockjaw defeated Thanos and stranded him in another dimension.

Pet Avengers, assemble !

Upon returning, Lockjaw forged a more powerful psi-link between the Pet Avengers, so they could assemble when another crisis threatened the world. He then returned the assembled gems to Black Bolt and Mr. Fantastic.

A short while later, Niels was given back to Robbie Baldwin for therapeutic purposes.

The Pet Avengers often operate in the Central Park area, which seems to be their unofficial HQ.

Astonishing tails

In 2010, the Pet Avengers valiantly fought Asgardian wargs  in Central Park. Though they were nearly defeated, an impromptu team-up with the Power Pack kids turned the tide and they subdued the magical wolves.

Soon afterwards, the Pet Avengers sought to find Frog Thor, who had gone missing while on a quest. They located him in the Himalayas. There, the pets helped him defend mythical creatures that were being chased away from an imaginary realm connected to children’s dreams.

The Pet Avengers and a yeti whom Frog Thor had befriended helped a unicorn named Daniella put the situation right. The mythicals  were safely returned to their dimension.

The Pet Avengers later responded to a crisis involving dragons led by Fin Fang Foom and teamed up with Captain America (James Barnes), Iron Man (Anthony Stark) and Thor (Thor Odinson), who had been turned into frogs.

However, the Pet Avengers realised that the dragons were actually trying to help. The animals thus ended up fighting the Avengers to delay them – Frog Thor being needed elsewhere, the animals couldn’t communicate with humans. Hairball and Redwing engaged Spider-Man (Peter Parker).

The crisis was soon resolved and Frog Thor came back to explain to the Avengers what had been going on.


Niels is a very orange house cat, though in one issue it was erroneously coloured white.

When the Pet Avengers use their telepathy — not a common occurrence — their eyes flow with white energy and there’s a “zrrt” sound effect.


For years, Niels was written as just a house cat, albeit one with a attitude. It liked getting underfoot and pouncing on things people were holding (especially large boxes), yet always shunned contact and hated when people tried to catch or touch it. Very independent and adventurous, it was generally misanthropic and living by its own rules.

After it coughed up its hairball, Niels became much more social and even-tempered.

Sapient personality

By 2009, Niels is portrayed as having human-level intelligence. He acquires the standard “cartoon cat” personality. As such he’s haughty, grouchy, dislikes dogs, tends to kvetch and complain about things incessantly. He’s also fairly intelligent and resourceful, snarky, and interested in eating birds and fishes.

Hairball is courageous, but not foolhardy. Still, he sees himself as a super-hero and will intervene in crises such as thefts or escaped dangerous animals.

Hairball face closeup

Being a cat, Niels wants to feel important and valued. He acts paranoid if he doesn’t receive attention, usually blaming Ms. Lion for that. He also doesn’t like it when somebody else does something cool as he feels upstaged.

Niels appears to be hydrophobic. This goes way beyond the usual dislike of cats toward water messing their hair, and has manifested as full-blown anxiety attacks and hysterical episodes.


Like other animals in this genre, Hairball has something of a one-track-mind and isn’t very good at changing subjects. His usual subject is how incredibly stupid Ms. Lion is. Unfortunately, Hairball and Ms. Lion are the only two Pet Avengers who live close to each other, so they have to pair up for their adventures without the rest of the team.

Generally, the Pet Avengers’ personalities and mental acumen is roughly at the level of children.

The all-ages Pet Avengers stories use cartoon/children’s stories genre convention, and people or animals do not get harmed. Thus, Hairball is portrayed like a cat as children imagine them to be rather than as an efficient hunter-killer of all sorts of small things, like many outdoors cats.


“I used to be called Niels, but if my master can call himself Speedball after our accident, I can be Hairball.”

“I hate this place.”

“You are a dog. There’s no way you could be as cool as a cat.”

(Having an anxiety attack underwater) “Hate the water, hate the dog, hate the turtles, hate the whale, hate hate hate…”

“Then again… we have been to *two* jungles with dinosaurs already. Will the next place have dinosaurs ?”

(Sarcastically) “Yeah, because no one will notice a giant bulldog or a saber-tooth tiger clomping around [the White House].”

Ms. Lion: “Cat, why are you always so mean to me ?”
Hairball: “It’s my job.”

Game Stats — DC Heroes RPG

Tell me more about the game stats


Dex: 04 Str: -03 Bod: 01 Motivation: Feline
Int: 02 Wil: 02 Min: 02 Occupation: House cat
Inf: 03 Aur: 02 Spi: 02 Resources {or Wealth}: N.A.
Init: 015 HP: 010

Analytical smell/Tracking scent: 04, Claws: 00, Directional hearing: 05, Enhanced initiative: 06, Extended hearing: 02, Jumping: 01, Kinetic absorption: 09, Mental blast: 01, Running: 05, Shrinking: 05, Speak with animals: 04, Super-hearing: 04, Ultra vision: 04, Telepathy: 10

Bonuses and Limitations:

  • Analytical smell/Tracking scent receives a +1CS penalty to OV/RV to actually track scents rather than simply smell something.
  • Jumping has the Catfall Bonus.
  • Shrinking is Always On and Already Factored In.
  • Speak with Animals is Form Function.
  • Telepathy – see below.
  • Enhanced Initiative, Jumping, Mental Blast and Running are Contingent Upon Kinetic absorption.
  • Mental Blast has Scattershot.

Acrobatics (Athletics, Dodging): 05, Acrobatics (Climbing): 03, Evasion (Ranged only): 05, Thief (Stealth): 03

Bonuses and Limitations:
Acrobatics (Athletics, Dodging) is Contingent Upon Kinetic Absorption.

Familiarity (Urban survival).

Pet Avengers (High).

SIF of immersion into water, Oblivious (when trying to discern colours or immobile objects or to use depth perception), Misc.: Cannot verbally communicate with humans, Misc.: Is a house cat and not generally treated too seriously by humans.

Pet Avengers assemble !

A psi-link exists between the Pet Avengers – they can use Telepathy with each other, though they usually just speak since mental communication requires much more concentration. This Telepathy has a Special +10 Range Bonus when it is used to simply transmit the “Pet Avengers assemble !” message and the rallying place.

It is possible for two or more Pet Avengers to use Telepathy and Team Attack against the Range if they are trying to locate a colleague thousands of miles away. They’ll usually be able to engage the +10 Special Range Bonus as they’re only trying to read the location.

Note that such a reading is sufficient for Lockjaw to use as a teleportation target.

By Sébastien Andrivet.

Source of Character: Marvel Universe (and particularly the Pet Avengers stories).

Helper(s): Darci, Capita_Senyera, Nicolas Lemaçon.

Writeup updated on the 1st of September, 2012.