As far as the cat specifically? Probably just for added cute factor.
For the fact that he's a cute loli in the first place, he's always been a known fag who wants to be a girl.
Most notably he once said pic related in an IRC.
The cat represent femininity and his desire to be a bottom bitch. He ditched it after his tragic breakup with W.T. Snacks and lost all hope. Snacks was the part of him that allowed him to go on even after all the years of sexual abuse. Anyway you look at it Snacks was the part that made him feel alive and have fun with this site and him leaving left a hole in 4chan. m00t can only imagine the sexual abuse Snacks must be going through right now as Bubba pounds his ass into oblivion as it's his only way to survive. Remember no one in prison stands up for pedophiles and after Snacks got caught with all that cp he had it coming. I don't really blame him though, Snacks was always kinda off.
Here I am rambling on about simpler times. Where did it all go when the two would post their nudes after a hard night?