Pikachu

You may cast Pikachu from your graveyard by
paying {r/w}{e}{e} instead of paying its mana cost.
First Strike, haste
At the beginning of your upkeep get {e}.
{t}, Pay {e}: Pikachu deals 4 damage to target
attacking or blocking creature. {t}, Pay any amount of {e}, Exert Pikachu:
Pikachu deals X damage to target permanent,
where X is the number of {e} paid this way.
(An exerted creature won't untap during
your next untap step.)