After realizing that the marshmallow may be self-aware, you want to confirm your suspision by delivering a turing test.
You scream inside the belly of the beast "Hello! What do you call yourself?"
At first you hear no response. And then, a deep rumble comes from all around.
"Stay Puft"
Do you:
Realize that someone has poured a bucket of water on you.
Realize that you are in the ghostbusters movie and wait for the marshmallow to explode
Be left clueless by this reference and try to eat your way out
Understand that you need Ghostbusters, and build a stay puft marshmallow man
Assume you're on a prank show and begin looking for Ashton Kutcher
Go Super Saiyan to roast the marshmallow with a Kamehameha
Ask ELIZA, who just happens to be running on a nearby terminal