Giant Bees are a rare enemy found in Majora's Mask. This type of enemy can be found in three notable locations, the Swamp Spider House, the Mountain Village during the spring time and lastly, the Pirates' Fortress. This form of bee appears to be very large in size compared to the average bee and it's very aggressive. The bees only attack Link if disturbed. When they are disturbed, they attack in swarms, however they pose little threat to the young hero and he can simply use the Spin Attack to kill them.
That's a Giant Bee.
Link can first encounter this form of bee when navigating his way through the Swamp Spider House. The young hero is tasked with finding 30 Gold Skulltulas, and a couple of them are situated within several beehives deep into the spider house. Link can shoot down the beehives using his Bow, however if he shoots the wrong one, the Giant Bees get angry and swarm round him. Link also encounters these bees briefly in the Mountain Village. After tackling Snowhead Temple, spring returns to the region and the Giant Bees come out to pollinate round the blossoming flowers.
Later on in the game Link must find and return the missing Zora Eggs to the Marine Research Lab. Four of the missing eggs are located within the highly guarded Pirates' Fortress. The young hero comes across a room, which is heavily guarded by several Gerudo Pirates, who throw Link out if caught. One of these Pirates is Aveil, who is guarding a secret treasure. The young hero must utilise his Bow and shoot the large beehive within the room. Doing so releases several Giant Bees, who attack the Pirates. This allows Link safe passage into the room, where he can find a Zora Egg and the hidden treasure, which is revealed to be the Hookshot.