Sk3tch

Also, her skin is extremely squishy and Wobbly (like a waterbed)

Appearance: An anomaly in the form of a drawings guidelines, to an eldritch beast of an unknown nature. Sk3tch’s biology is still fully figured out, but her face can contort and her eyes can glow red once she is threatened. She doesn’t talk, but she is aware of what’s happening both outside and inside of reality

but you don’t care about that, you wanna know what that ass do.

Her powers are unknown, but she can in fact grow, mesh and stretch to make her ass bigger. She can also grow appendages (tits, lips etc)

You are in her house