PROFESSOR
GROWLINSKI PROFESSOR
GROWLINSKI
Real Name: Growlinski (possibly her full name)
Identity/Class: Alternate Reality (Reality-85324) extraterrestrial (Thunderan, relocated to Third Earth)
Occupation: Scientist and inventor
Group Membership: None (unless all Thunderans are Thundercats, in which she is, too)
Affiliations: Thundercats (notably Lion-O, Cheetara, Lynx-O, Panthro, Snarf, Tygra; although the latter four never met them and doubted their existence)
Enemies: Evil Mutants
(notably Jackalman, Monkian, S-S-Slithe)
Known Relatives: Leoperra (twin brother),
unidentified parent(s)
Aliases: None
Base of Operations: A
thermal tent north of Hook Mountain, Third Earth;
formerly Thundera
First Appearance: Thundercats#56: Designer Thundercats Winner Fact File (April 9, 1988)
Powers/Abilities: Professor Growlinski is a
brilliant scientist and inventor.
Her brother, Leoperra, via linking with
her mind, can create a protective force field.
History:
(Thundercats#56: Designer Thundercats Winner Fact
File (fb) - BTS) - It is said that during the Month of the Twin, twin
starts were born in a distant galaxy that will burn brightly for
millions of years. In that month were also born two Snow Leopards: The
brilliant scientist and inventor Professor Growlinski and her foolish
but keen athlete brother, Leoperra.
When Thundera was destroyed, both Growlinski and Leoperra boarded a Thundercat Ark Ship. Before the ship was destroyed by the Mutants, they ejected in an escape-pod bound for Third Earth.
Both subsequently lived in a thermal
tent north of Hook Mountain, made from the outer shell of their escape
pod.
(Thundercats#90/2 - BTS) - Thundercat leader Lion-O had collapsed in the snows around Hook Mountain during a blizzard while he was trying to join Snowman on a hunting trip.
(Thundercats#90/2) - Observing Lion-O's plight, Professor Growlinski donned a hooded coat, approached him and grabbed his arm to assist him.
(Thundercats#90/2 (fb) - BTS) -
Growlinski brought Lion-O back to her thermal tent.
(Thundercats#90/2 - BTS) -
Meanwhile, the Evil Mutants (notably Jackalman,
Monkian and S-S-Slithe) launched a massive snow boulder into Cats' Lair,
in the Plain of Fertility.
(Thundercats#90/2) - When Lion-O awakened and he saw Professor Growlinski's feline eyes, he asked if she was a Thundercat. Laughing, she told him that it didn't matter where she came from but that she and her brother, Leoperra, lived to the north of Hook Mountain. She advised him that he was way off course.
Considering that there couldn't be any other Thundercats on Third Earth and wondering if he was gripped by "snow-madness," Lion-O told the professor that she must help him.
As the Evil Mutants continued to launch
snow boulders that progressively covered Cats' Lair, Professor
Growlinski and Leoperra drove a vehicle (with
Lion-O as their passenger) in front of the lair.
They then projected a beam from their vehicle, and the Plain of
Fertility was soon engulfed in clouds of steam as the massive snowdrift
began to melt.
(Thundercats#90/2 - BTS) -
Growlinski and Leoperra left Lion-O by the lair and departed in their
vehicle.
(Thundercats#90/2 - BTS) - Realizing that there would be trouble when the Thundercats were freed, S-S-Slithe led the Evil Mutants to flee.
(Thundercats#90/2 - BTS) - By the time the steam had died down, Panthro asked Lion-O -- who was still dazed from his chilled experience -- if he had used the Sword of Omens to melt the snow. Lion-O replied that it had been two Thundercats -- snow leopards, from Hook Mountain -- but the other Thundercats laughed, and Lynx-O stated that the snow madness had gotten to him after all.
(Thundercats#90/2) - As the Evil
Mutants hauled the Thundercatapult through a steep-sided, frozen valley,
Leoperra fired his phaser rifle, causing an avalanche of icy boulders
and snow, burying the mutants and their weapon.
Leoperra asked Growlinski if she
thought they had overdone it a bit, but she told him, "No...Let's
face it -- you'd have to be snow-mad to trespass in the Kingdom of the
Ice Cats!"
ThunderCats is a media franchise, featuring a fictional group of cat-like humanoid aliens. The characters were created by Tobin Wolf and featured in an animated television series named ThunderCats, running from 1985 to 1989, which was animated by Japanese studio Pacific Animation Corporation, and co-produced by Rankin/Bass Productions.
The ThunderCats franchise simultaneously launched a line of action figures produced by LJN and a syndicated after-school weekday cartoon.
The original ThunderCats show was animated in Japan while being produced, written and voice acted in the United States.
The series was distributed by Rankin/Bass Productions' then-parent company Telepictures, which would later merge with Lorimar Television in February 1986. In January 1989, Lorimar-Telepictures was purchased by and folded into Warner Bros. Entertainment, whose television syndication arm would eventually assume distribution of the show; Warner Bros. has owned the rights to the series (and all Lorimar-Telepictures programming) from that point on.
A ThunderCats comic book series based on the animated series was published by Marvel Comics through its Star Comics imprint in 1985, lasting for three years and twenty-four issues. During this time, a new series was published by Marvel UK consisting of 129 issues and was also published for three years.
Wildstorm and other companies have subsequently published Thundercats comics.
What Reality?
The world they were based on was called "Third Earth" - that alone would imply some connection to the original Earth. Arguably that alone might mean it was a human colony world at some point (e.g. original Earth by default becomes First Earth when the first colony is established and is named Second Earth, and then the next colony planet becomes Third Earth), but then in an episode Mumm-Ra states "I have known of its power for a thousand years, from a time when this was still First Earth", meaning that this is apparently Earth renamed. And then there's the episode Excalibur, where Mumm-Ra learns that the most powerful wizard in Third Earth's past was Merlin, who made Excalibur for King Arthur, and Mumm-Ra proceeds to retrieve said sword from the Lady in the Lake's lake - so it really seems the Thundercats are just on Earth some time in the distant future.
The US and UK stories are presumably the same reality. Once the UK title ran out of US material to reprint (possibly even before it ran out) they produced their own stories. Unlike Transformers, where new US stories then contradicted some things the UK version did, splitting off a new timeline, there were no further US tales for Thundercats and so no divergence.
Without comparing both cartoon and comics thoroughly I couldn't say if they are the same or different timelines. I'm sure the plan was for the comics to be in the same version of events as the TV show, but given the TV show kept going for four years, there's every chance that something in a later episode contradicted something the comics had established. I think I'd designate the comic reality, but not list the TV show separately, and note that they might be the same reality, but also might not be.
Almost certain that subsequent Thundercats comics aren't the Marvel
version's reality, for similar reasons. There's a good chance they
introduce something sooner or later than clashes with what the Marvel
comics did. But again, not a definite. There are also later versions of
the cartoon, and those are definitely different realities.
--Loki
This profile was completed 06/26/2026, but its publication was delayed as it was intended for the
Appendix 25th anniversary 's celebratory event.
Thanks to Loki for suggesting Professor Growlinski to
represent the Thundercats (and cleaning up the images): She
(and her twin brother) are the Charcoal/Humus Sapiens of Thundercats -
winning entry in a competition.
Profile by Snood.
CLARIFICATIONS:
Professor Growlinski should be distinguished from:
First posted: 09/19/2026
Last updated: 06/26/2026
Any Additions/Corrections? please let me know.
Non-Marvel
Copyright info
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