Maybe creating a new "monster boy" tag to separate from the tag "monster girl". But then again there's the tag "monster"...

I don't know why this tag is not famous... I aways wanted to separate the male goblin and female goblin tag. I don't like goblins but I like female goblins, and I can't search like "goblin" + "monster girl" because I have blacklisted "goblin" and "orc" tags.