Gravebore Wurm

Trample

Disillusion {2}{g}{u} (If you mill this card, mill it
into exile. When you do, cast it for its disillusion cost or put it into your graveyard.)

If you cast Gravebore Wurm for its disillusion cost, when it enters create a 6/6 blue Wurm Illusion creature token with trample and "When this creature becomes the target of a spell or ability, sacrifice it".

It feasts on the memories of the forgotten.