This is a picture of Calvin, one of Toasty's preschool students. Calvin really looks up to Toasty as a role model, and here he is giving his teacher a hug. Totally does not want to hug back because he does not want to give the wrong message, but he does admire the appreciation of Calvin. He admires being looked up to as a role model. Although he is not related to Calvin in any way, he does not mind when Calvin calls him Uncle Toasty.

As for what Calvin is wearing. He is kind of a Monstrum equivalent of a furry.