The snake stopped, poised as if to strike, then tilted his head to the side, and nosed at the side of the squirrel's head. He was making an odd hissing sound that was as close to laughing as a snake could produce, and then he hissed one last time and was Robin once more, and a laughing Robin at that.
"You can change into anything you want, sister, and you couldn't think of anything but squeaking?" He was quite amused by her lack of survival instinct, yes.