Lazav, the Multifarious

When Lazav, the Multifarious enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

[Variable Colorless]: Lazav, the Multifarious becomes a copy of target creature card in your graveyard with converted mana cost X, except its name is Lazav, the Multifarious, it's legendary in addition to its other types, and it has this ability.