You are blowing this way out of proportion.
Quit fapping yourself into a coma and listen for like, five seconds.
It's a bunch of a avatars based on a character from a bloody webcomic.
Nothing else.
The other two were there for a long time, you're just oblivious to minor details.
The forum hasn't been "invaded" by furries.
They just like a webcomic, and use an avatar to show that.
Nothing else.