From Zelda Wiki, the Zelda encyclopedia
The Death Bugs are mini-bosses found in Freshly-Picked Tingle's Rosy Rupeeland. They are located inside of Insect Cavern, and there are three in all. Their bodies emit a noxious gas which will poison even the stoutest of souls.
To gain passage through the cavern, Tingle must destroy the bugs by throwing a total of three Tingle Bombs at each. The Death Bugs are partly buried beneath the earth within the cavern, with only their heads appearing above the surface in the overworld.