It's Wolverine's baby with Mystique from an alternate timeline. He did come to 616 briefly, and that's when Logan realized he couldn't risk having sex with Mystique again.
He has Wolverine's claws & can shape-shift like Mystique. Raze-2.jpg
So Mystique got impregnated by both Sabretooth and Wolverine(alternate universe I know)? Ain't that some... she must be into that ferocious animal-like love making.