Beenade

Beenades are a type of explosive dropped by the Queen Bee boss, which act similarly to the Grenade. Upon exploding, a swarm of Bees are released, which will follow the nearest enemy. Bees appear to stay until there are no more enemies left to attack, or they have been killed.

Based on early tests (more precise numbers have yet to be determined), a single beenade can deal upwards of several hundred points of damage, at least when thrown at the Eye of Cthulhu. A single beenade can also easily defeat groups of 4-5 Face Monsters and Blood Crawlers. It's also a good idea to use these against the Goblin Army, as the bees and the beenade will damage multiple goblins. Also decent against the Eater of Worlds.