Thought-Tiller

Thought-Tiller enters the battlefield as a
Siphoned copy of any creature on the battlefield
(If a creature becomes a Siphoned copy of a
creature, copy all permanents attached to that
creature and attach them to the copy)
If Thought-Tiller were to enter the battlefield
without copying a creature, it's base power and
toughness become 4/6 and it gains Double
Strike and Vigilance