Boris is the counterpart of the Cheshire Cat; like the character he is based on, Boris loves riddles. He has functional cat ears and a tail, several piercings and tattoos, and dresses in short, exposing outfits with a pink boa and a collar with a chain. Boris works in the Amusement Park District for Mary Gowland. Though he is sly, devious character with a childish persona, he becomes close to Alice. He is friends with Dee and Dum, despite the fact that they work for opposing groups, and even goes to Hatter Mansion to have tea parties and interact with Elliot and Blood. Boris has on numerous occasions, snuck into the Castle of Hearts. When his luck ran out, Alice found him badly wounded and bloody, and after a reprimanding from Alice, Boris promised to change his careless and ruthless ways for Alice's sake.

When Ace threatens to kill Alice, Boris only shoots at his feet saying, "I can't kill you because it would make Alice sad." He gets mad at Ace when he kills in front of Alice.
Like many others in the Land of Hearts, he also falls in love with Alice.

(Source: Wikipedia)