Since it isnt a creature, you cant pay anything to turn it face up
It gives vigilance and +1/+1 for each charge counter, which you get whenever a creature enters under your control
That's why these limited sets are sure to sell out
For example, if Clive's Hideaway's hideaway ability is copied and two cards are exiled, you may cast both exiled cards without paying their mana costs (assuming you control four or more legendary creatures at that time.) Gogo's ability can copy any activated or triggered ability on the stack, not just one with targets
It costs a lot at six mana, but the chance to wipe the board and outright kill an opponent through the lifeloss Massacre Wurm causes makes it one of the scariest cards in the Starter Collection
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