He looks shocked and lays motionless for a second. Then his tails start wagging. "Really?"
"Yes really, but we need to lay down some ground rules."
"Oh, of course!" He smiles and pants.
"First, I'm in charge. You listen to me."
"Okay, that sounds good to me," he chirps.
"Second, we'll take shifts sleeping. Can I trust you won't go to sleep on your shift or try and eat me if I'm asleep?"
"Of course not, we're teammates! Teammates don't eat eachother. And at night, I'll keep a watchful eye." He seems genuine but you can see his very sharp teeth. You just hope this whole team thing doesn't come back to bite you, literally.
"And third..." you pause. You were about to tell him no hunting other Pokémon. It's a value you hold dear. Eating meat, even if pikachu are technically omnivorous, is considered a great sin in the tribe. It's said if a pikachu eats meat they go crazy and become ravenous feral cannibals. You were raised right so you believe this. Even so, he is a predator and will have to eat at least bugs but you could ban the eating of more sentient Pokémon, like pidgey. Then again sleeping with a hungry predator might not end up well. What do you tell him?