Slither, Swamp Lurker

Companion - Each permanent card in your
starting deck has an even converted mana cost.
(If this card is your chosen companion, you may cast
it once from outside the game.)
When Slither enters the battlefield, each player
puts the top four cards of their library into their
graveyard. Put a creature card with an even
converted mana cost from among those cards
onto the battlefield under your control.