Bat Scepter

Every cast throws out a couple of bats that fly straight for a moment before they start hunting. They pick the nearest enemy, switch if something closer wanders in, accelerate hard once they have locked on, and turn around quickly when they overshoot. What they will not do is enter water or lava, and they ignore anything standing in liquid unless that enemy can also move through blocks.

Single targets with room around them. The homing handles the aiming, so it keeps working while you are busy dodging and never firing straight. Give it a boss in an open arena and it is one of the better wands of its era.

Ceilings. The bats need space to curve and they die against walls in the Dungeon or any tight corridor before they reach anything. Crowds are the other weak point, since a bat does not pierce and expires on the first thing it touches, so an event wave outpaces the fire rate. The Wasp Gun handles both of those better while losing badly on a single target.

It is the Halloween answer to the Bee Gun line, down to the swarm behavior, and casting it plays the same sound as a pair of wings.