Megatron, Decepticon leader

Hexproof,infect, indestructible, menace
Whenever a construct you control deals combat
damage to a
player, you may pay {x}{u/b}.If you do, exile the top {x} cards
of that player's library. At any point, you may cast
a card from
exile without paying it's converted mana cost.
{u}{b}{ut}:Create 2 5/5 blue and black construct creature tokens