User blog comment:Xilinoc/Ch. 596 - Rubb-Dolls 3/@comment-24913480-20140910202507/@comment-5398287-20140910211214

Well, I think PePe's "monster" is different from Gremmy's "monster". On the whole, PePe is not overwhelmingly powerful; his power boils down to making others fight for him, and it can be dodged or resisted by sufficiently powerful individuals. Meanwhile, Gremmy was wielding imagination and was completely insane: there was no way that anyone could counter his power, and he ended up killing himself by accident because that was basically the only way to resolve the fight at that point. Honestly, PePe getting taken out this easily is no surprise to me; he's a one-trick pony with no real combat powers.

To sum up: PePe is a monster because of the nature of his power (tis creepy as heck), while Gremmy is a monster because of what he can do with his power.