Sleipnir

Bestow {5}{b}{b}(If you cast this card for its bestow
cost, it's an Aura spell with enchant creature. It
becomes a creature again if it's not attached to a
creature.)
Haste, trample, doublestrike
Echanted creature gets +3/+3 and has haste,
trample, and doublestrike.
Who are the twain that on ten feet run? Three eyes
they have, but only one tail.