Dr. Wheelo, Living Fortress

Defender
When Dr.Wheelo Enters, create two 0/3 wall tokens with defender.
{u/b}: Create a tapped 1/1 Drone token.
{u/b}{u/b}: Create a tapped 0/1 Drone token with defender and "{t} deal 1 damage to target attacking creature"
{4}{u/b}{u/b}: Exile target creature card from a graveyard with mana value 5 or less, return that creature under your control to the battlefield.