Oracle Text

Enchant creature

R: Enchanted creature gets +1/+0 until end of turn.

Card Rulings

10/1/2009 This ability can be activated by Firebreathing’s controller, not the enchanted creature’s controller (in case they’re different players).
10/1/2009 The ability affects whichever creature is enchanted by Firebreathing at the time the ability resolves. The bonus remains even if Firebreathing stops enchanting that creature.