Drag Tentacles are long, thick tentacles that are only encountered in a few instances. They normally come from holes in the wall and their appearances, whether still there or not, are very easy to notice. Drag Tentacles have a weak spot on the back side of them, which is a yellow pustule. When you destroy this pustule the Drag Tentacle explodes. Drag Tentacles attack their victims br randomly spawning out of holes in the walls, ceiling, or floor and grab ahold of their victim and try to drag them into the wall. If successful they slaughter their victim, regardless of whether the victim can grab ahold of something or not. They are used by The Leviathan and The Hive Mind but could also just be giant extensions of The Corruption.
Even after killing the Leviathan, they still appear.
Isaac has a flashback of being attacked by one when he revisits the USG Ishimura.
The Hive Mind uses them to prevent Isaac from escaping, but do not have a yellow weak spot on them.
They are encountered quite often when you have to move the Marker.