Blue Twirlers (called "Smashers" in the strategy guide) are slow moving smashing ghosts found in Luigi's Mansion.
When encountering the Blue Twirlers, they will smash Luigi with their fists when he's close to it. It can cause a great deal of damage to hurt Luigi.
Luigi doesn't need ice to freeze it unlike the Blue Blaze, or if he uses it, that wastes it so he shouldn't underestimate the number of his ice and when it's in low health, he can use it.
Once any other ghost is behind it as it want to smash him, he must shine his light on it and vacuum it to death.
Blue Blaze: A Blue Twirler that's weak to ice and has a water element.
The Blue Twirler appeared as a trophy in Super Smash Bros. Brawl.