Thunder Totem

Oracle Text

T: Add W.

1WW: Thunder Totem becomes a 2/2 white Spirit artifact creature with flying and first strike until end of turn.

Card Rulings

8/1/2008 A noncreature permanent that turns into a creature can attack, and its abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature.