The Ur-Squirrel

When The Ur-Squirrel enters the battlefield,
create a 1/1 red Squirrel creature token with
riot.
At the beginning of your upkeep, create X
1/1 red Squirrel creature tokens with riot
for each squirrel You control.
{1}{r}{g} {t}: Create a 1/1 red Squirrel creature
token.