Bestial Fire-Breather

Whenever Bestial Fire-Breather attacks, if defending player controls a creature with a higher power than Bestial Fire-Breather, you may pay {x}{r}{r}. If you do, Bestial Fire-Breather gains First Strike until end of turn.
Whenever Bestial Fire-Breather attacks, if defending player controls a creature with a higher toughness than Bestial Fire-Breather, you may pay {x}{b}{b}. If you do, Bestial Fire-Breather gains Double Strike until end of turn.