User blog comment:MrAnonymous/I think I know what the lizard thing is./@comment-66.130.243.133-20120607022252

There is clearely more then one of these things because the one that killed Isaac's father didnt had a tail and the one in Isaac's house had a tail, so maybe this one is like an "alpha" for this kind and the other one is like a "beta".(Im not saying they are alpha and beta, im just giving an exemple.)