Goomy Shroomy cant be cast from your hand or library.
Convoke
When Goomy Shroomy enters the battlefield under your control, destroy all nonland permanent. Goomy Shroomy gets +1/+1 counter for each creature destroyed this way. You gain life equal to the mana value of all enchantment destroyed this way. You shuffle spore token in all player libraries equal to the number of permanent destroyed this way.
Escape
: Exile your graveyard.