1 Rock monster in your GY + 1 Level 4 or lower monster Must first be Special Summoned with "Fossil Fusion". When this card destroys an opponent's monster by battle: You can inflict 600 damage to your opponent. You can banish this card from your GY; add 1 monster from your Deck to your hand that mentions "Fossil Fusion". You can only use this effect of "Fossil Machine Skull Buggy" once per turn.