
At the beginning of your upkeep, put a +1/+1 counter on this creature.
This creature can't attack or block unless you pay {1} for each +1/+1 counter on it.
Myr Prototype has 1 printing, first in Mirrodin (2003). EDHREC ranks it #23,514 among Commander cards.
Cards that show up in the same decks on EDHREC.