When to Introduce a Hook Horror into Your Campaign
The Hook Horror has a very straight-forward stat block in the 5e Monster Manual. It gets two hook attacks, it can climb, and it prefers to ambush prey. Other than that, we get a lot of information about the creature’s use of echolocation to find food in the cavernous systems they dwell.
Combining all these facts, you should bring a Hook Horror into your campaign while its in a subterranean environment and if you want to play cat-and-mouse with your players. Everything the manual gives you sets up a horror encounter: From the eerie clicking noises it makes, to its surprising agility and terrible appearance, the Hook Horror asks the DM to back up the fact that its a “horror” to fully bring this classic D&D monster to life.
How to Introduce a Hook Horror into Your Campaign
While exploring a cave system or other underground dungeon, describe the distant sound of clacking or tapping along the rock walls. You want a noise to precede the creature to add a sense of dread to the impending battle. Sometimes the noises lead to nothing… sometimes the noises are suddenly closer and then the Hook Horror is already upon you. Leave traces of its past victims around the lair, and make it gruesome. Your players should be saying, “What could have done something like this?”
Play up the hunter aspect of the unnamed monster and never let the creature be ganged up on. The Hook Horror should strike when the party is divided so that it can kill or harm whatever it selects as prey as fast as possible before disappearing again. Perhaps the creature is so fast that its barely seen, and the best way to deal damage to it is during an attack of opportunity while the Hook Horror flees.