Jasper "Cosgrave" Deepswamp is a mutanthorned toad (which is actually a kind of lizard) and a member of a team of scavengers led by Dwayne Kowbird. He's had to fend for himself his whole life, and has only stayed alive due to using his psionic powers to fend off human and mutant attackers. He trusts no one, but hangs with Dwayne's crew because he believes there is safety in numbers. He would have no problem abandoning them if he found the opportunity to do so.
Cosgrave loves making fun of others, and will do so at any opportunity. However, he cannot stand for it to be done to him.