Hornet

Hornets are inhabitants of the Underground Jungle biome. They are airborne and normally spawn in groups, to represent the swarming nature of real Hornets. Like Demon Eyes, they move away from you when you hit them and then charge back at you. It is advised that you corner them up against a wall to kill them effectively using a flail or Muramasa. Due to the darkness of the jungle, a Hunter Potion makes it easy to spot them before nailing them with a bow.

Hornets can be very deadly in groups as they spawn quickly to accumulate in a swarm. They deal an attack damage of 40 modified by the player's total defence. They drop very rare items including the Blade of Grass, Thorn Chakrum, as well as the elusive Ivy Whip.

Hornets, as of 1.0.6, fire a projectile that has a 1 in 3 chance to poison the target. These projectiles cannot go through walls, similar to a Harpy's feather. With this is mind it is easy to make a floating rest area to recover health as long as you are out of reach of man eaters.

Update Info
Hornets have been known to 'flip over' as they turn, but this was fixed in the 1.0.4 update. 1.0.6 - Hornets now fire a projectile.