The Sleepy Trainer/Rare Trader raises the leader's stats, and can teach the leader the Sound Sleeper trait, at the expense of being kicked out of the camp.
This person is asleep. How could they sleep so soundly in the middle of the zombocalypse? Right on the ground, no less. He/She must have it all figured out.
Stat upgrade 1:1 food
[Character] jams food in the sleeping petrson's face.
He/She talks nonsense in his/her sleep. Or at least it sounded like nonsense at first. [Character] thinks about it and realizes it's valuable knowledge.
Stat upgrade 2: 2 food
Sound Sleeper trait:4 food, at the expense of being kicked out of the camp
[Character] starts to understand his/her perfect zen tranquility, and learns the SOUND SLEEPER ability!
Someone notices that [Character] has been jamming large amounts of food into a sleeping person's mouth. HEY! YOU GET OUT OF THIS CAMP RIGHT NOW!
The group runs away, fleeing from the trader camp!