Create a 0/0 green Ooze creature token with
trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.). Put X +1/+1 counters on it, where X is two plus the total number of cards you own in exile and in your graveyard that are Oozes or are named Slime Against Humanity.
A deck can have any number of cards named Slime Against Humanity.