Guardian of the Spear
Monster Manual classification: Unknown
Alignment: True Neutral
Organization: Four at a time.
Special Qualities: Incorporeal
Description: If you only use single-target attacks on the giant, the ghosts will ignore you and attack him as well. While they deal very low damage, they can be used to lock the giant on a corner.
They can never be truly destroyed. As soon as you defeat one of them, another one will spawn to continue the fight.