Multiple hookrats (3) at the same time at the same place leads to some wierd behaviour. I noticed if the hookrat has no room or a specific time of dragging and then standing his polearm up, then it will change direction no more, just stuck on a wall (not in a corner), marching in one place. if some overlapping issue happens on the ground, it just literally vanishes from player’s sight, cannot be targeted or even seen anymore, but it drags the player into the gap of overlapping terrain. the rat basicly set itself to godmode, it exists, just has no hitbox to target. bombs could not kill it either.
This pic was taken on the Engines of War exiting the wood tunnel, heading to drop down for the barrel event destroying the doomwheels