Seeing a trophy with elaborately carved ivory, you grab it and run back to the window - but before you get there you start feeling bloated.
Feeling your stomach getting heavier, you sink to all fours as the heavy feeling intencifies.
Your body grows heavy and you start getting bigger and bigger, your arms turning to front legs, your hands becoming huge round feet to match your own back ones. Your ears grow to massive flaps, your nose elongates into a large prehensile trunk, and a pair of tusks grow out of your mouth.
You have turned into an elephant!