John, of the Long Turn

Whenever a creature you control deals damage to another creature, the opposing creature gains
a +1/+1 counter.
{w}{u}{g}{t} Create a 1/1 green fox creature token
with: “When this creature dies, proliferate.”
At the beginning of your upkeep, if the total
number of +1/+1 counters on creatures you
don't control is greater than 20,
you win the game.