Mud Can't Turn Into Anything

Mud can turn into whatever animal you see, right? So we see the thing. We leave it alone. You turn into the T-rex. We go in. We kill humanity. I shoot him in the head with an arrow. Not to go too meta, but I'm pretty sure Gus and Micah made it a T-rex because it's a creature that's not in the list of creatures I can turn into. There are some rules in this game. Well, you just got to see it,. That's the thing. I'm telling you, I can't. mud can't turn into everything.