power napper
A person who can fall asleep/take a nap at anytime of the day, at any place in the world, in any situation and then wake up like a Phoenix reborn from the ashes.
Tom: Wow how can you fall asleep that fast? We were chatting fine and the minute I looked away, you started snoring.
Carrie: What can I say, I'm a power napper.
Carrie: What can I say, I'm a power napper.