The Male Dragonfly is one of the 24 Golden Bugs that can be found in The Legend of Zelda: Twilight Princess. The Male Dragonfly can be given to Agitha for a rupee prize. Once all 24 Golden Bugs have been collected, Agitha will give Link the Giant Wallet, a massive wallet that can hold up to 1000 rupees.
The Male Dragonfly can be found in Zora's Domain. Once Link enters the Zora's Domain area, go to the west (Wii) side and climb the ramp. Floating atop some grass about halfway up the ramp will be the Male Dragonfly. The Female Dragonfly can be found in Zora's River just south of Zora's Domain.