He'll hop out. We'll just have to watch he doesn't immediately roll around in the dirt, as he's known to do. The last time I tried to bathe him without you, he ended up taking two baths, because he was dirtier afterward than when we started.

[Sokka grabs up one of the dry towels and holds it out, ready to catch Appa as soon as he jumps out.]

Okay, get ready to hide so he doesn't shake on you. One, two--

[And before he can finish, out hops Appa, immediately shaking out his fur all over the place.]