I found the secret place of this monster. The little blue neurons call him Krrrz.
What's he like? Krrrrz seems very nice, but he likes to bully the bigger monsters. He's on good terms with the little blue neurons, although they are sometimes wary of him because he's unpredictable.
But I think he's lonely and very kind inside. Maybe there will be someone who can tame him and be a good friend to him.