"Magic 2013", +"life total", +!become, +!"can't change", +!redistribute, +!"set to" (2)
+1: Put a +1/+1 counter on up to one target creature.
−3: Target creature gains flying and double strike until end of turn.
−8: Create X 2/2 white Cat creature tokens, where X is your life total.
Serra Avatar's power and toughness are each equal to your life total.
When Serra Avatar is put into a graveyard from anywhere, shuffle it into its owner's library.
Gatherer works better in the Companion app!