This isn't Skull. This is a copycat sent back to placate Scratch. This is the only explanation I can think of for what we're seeing here.
I know canonically speaking, Skull was shown to be something of a standard monster back in the middle ages. And every now and again he's shown glimpses of his "true self", though largely it's been played for laughs when it happens.
This comes off as a huge leap out of character for the big blue gorilla.
Art nitpick: What's up with his upper lip in panel 2?