Once Patchwork Beastie is attacking or blocking, reducing the number of card types among cards in your graveyard won't remove Patchwork Beastie from combat.
Delirium — This creature can't attack or block unless there are four or more card types among cards in your graveyard.
At the beginning of your upkeep, you may mill a card. (You may put the top card of your library into your graveyard.)
