When I was discussing this with her dad he brought up the "where did he get that from" issue. I don't know the answer, but it could have been a superhero cartoon for all we know. I don't think it means abuse, necessarily. I talked to his mom at a birthday party once and quite liked her. That being said, I have no intention of having a conversation with his mom about it. I reported it to the director who runs the daycare. She can address it with the teacher, child, parent, whatever she feels is appropriate. That's her job.
My son went through this in 1st grade. He would tell me his "friend" would call him names, "stupid, ugly, etc.", I am not into bullying but also not going to make a big deal out of it either and would tell my son not to listen to him, ignore him, etc. Then, the teacher told me one day that my son was upset and said he was going to kill himself. I was so upset and when I talked to my son about it he told me his "friend" told him that no one liked him and he should just kill himself. I was livid. I went to the school the next morning with my son and talked to the teacher, vice principal, and principal and let them know what happened. The boy did get in trouble (although they would not tell me what exactly the punishment was) and the teacher assured me she would keep a very close eye on him to make sure there was minimal contact between them. It's a sad world we live in when small children say such horrific things.