#2. Slimer, The Real Ghostbusters
For a long time, it was mandatory for all cartoons about crime fighters, adventurers, rock bands and ghost hunters to have a pet mascot with a speech impediment. The Real Ghostbusters good-naturedly tried to adhere to that rule while paying homage to the original movie. The trouble was, they weren't really spoiled for choice in terms of characters. The only real options were that party pooper ghost that reads books, the spirit of a dead fat man or the monster-dog that lives in Dana Barrett's fridge.
Children will be so torn over which one they love the most.
Regardless of which supernatural being they chose, there would always be the weird underlying issue of a ghost helping the living to eradicate other ghosts. It's like if Sacagawea's entire contribution to American history was helping settlers subjugate Native Americans.
The Ultimate Betrayal
Cracked has mentioned before the horrifying implications behind the work of the Ghostbusters. Upon discovering that life exists after death, the three scientists respond by trapping that life in a tiny box, presumably for eternity. Equating it to a prison doesn't even do it justice. The holding center for all the spirits is more like an internment camp for the supernatural, and helping to cram all the ghosts into a box, ensuring them an eternity of misery, is the lovable Slimer. That is, when he's not busy eating a bunch of cheeseburgers!
Slimer is the only connection between worlds. He is the only ghost who can explain to the Ghostbusters that what they're doing is wrong. In fact, he's the only ghost who can even open his mouth in their presence without fear of it being violated by a thick proton stream. Yet he does nothing. Worse than nothing, he helps round up all the spirits and lock them away in exchange for hoagies. Every single ghost in existence must despise that duplicitous fat asshole.
#1. Gizmo, Gremlins
If you could isolate the most adorable characteristics from every pet imaginable, surgically remove those features and then sew them all onto one superpet, you would have a Mogwai. For anyone who's horrified by that prospect, prepare to be adorified by one driving a remote control car.
Gizmo is the original Mogwai in the movie and also the accidental source of all Gremlins that overrun a town. But like any responsible protagonist, Gizmo does what he can to clean up the mess by killing off the Gremlins. There's just one problem ...
The Ultimate Betrayal
Each one of those Gremlins is just the adult version of a Mogwai, and what's more, they are all the offspring of Gizmo. From a purely biological standpoint, Mogwais are creatures that reproduce asexually when exposed to water, and they live through two stages of life separated by a metamorphosis. Just like a caterpillar building a chrysalis and becoming a butterfly, the Mogwai encloses itself in a cocoon after gorging on food and grows into a Gremlin. Gizmo is essentially a Gremlin stuck in the larva state who refuses to take the necessary step (eating after midnight) to grow up. Not only does he hate the adult version of his species, but he actively helps the humans execute them.
Gizmo is like a worse version of Hellboy because he doesn't have the long history with a person to explain his loyalty to humanity. Gizmo is only Billy's pet for a few days before turning his back on the entire Gremlin species in favor of his owner. Then Gizmo murders his children in an effort to stop the proliferation of his own race.
Ultimately, Gizmo is a maladaptive, self-hating creature that actively tries to end his progeny. No wonder the other Mogwai hate him so much.
If Mogwai ever build a statue, I think we all know who it will actually commemorate.
For more from Soren, check out 4 Steps to Staying Relevant as a Bully In the Modern World and 5 Awesome Parasites That Torture Animals (That I Hate).