RevavroomvsSwellow

"It creates a gas out of poison and minerals from rocks. It then detonates the gas in its cylinders—now numbering eight—to generate energy."

"SWELLOW flies high above our heads, making graceful arcs in the sky. This POKéMON dives at a steep angle as soon as it spots its prey. The hapless prey is tightly grasped by SWELLOW’s clawed feet, preventing escape."