Crawling Horrors are large, tick-like Shadow Creatures with many legs. They are the most common type of Shadow Creature. When killed, they drop 1-2 Nightmare Fuel and restore 15 points of Sanity.
When the player's Sanity is above 15%, faint Crawling Horror shadows will wander around and move away from the player when approached and occasionally teleport to another location near the player. Crawling Horrors become aggressive when the player's Sanity drops below 15%, and their Sanity aura will further decrease the player's Sanity by -100/min. A Crawling Horror will telegraph its aggression by standing upright and baring its teeth while producing a shifting, warping growl. This audio cue is also used when the Crawling Horror/Nightmare attacks.
The Crawling Horror has a slower movement speed than the player and can easily be outrun, but does not lose aggro until killed or the player regains a state of sanity. Moving between the Caves and the Surface World will stop the horror from chasing the player.
Crawling Nightmares are a version of Crawling Horrors that spawn from Nightmare Lights in the Ruins and Nightmare Fissures in the Caves during the Nightmare Phase. They spawn and are aggressive regardless of player Sanity level, and despawn during the cooldown period when the Nightmare Phase ends. They produce the same noises as Crawling Horrors, but with increased echo and distortion. In 
they may drop nightmare fuel when they despawn, but in 
they usually don't. Crawling Nightmares will drop 1-2 Nightmare Fuel if killed before the Nightmare Phase ends, but will not restore Sanity.
Fighting Strategy[]
Fighting StrategyCrawling horrors become one of the easiest shadow creatures to deal with, simply because they are so common that players gain practice. See also the General Kiting Strategy for Shadow Creatures. Crawling Horrors are slow. To save time, run toward them, then reverse direction to dodge at the last minute.
Don't Starve Together[]
In addition to the General Kiting Strategy for Shadow Creatures, a more advanced player can usually sneak in a quick first hit before dodging. This requires holding F to advance and swing, then running away during the sound of the swing. The goal is for the player to be running away as the hit lands. Better to run too soon and miss than stay too long and get bitten. A speed boost such as a road or cobblestone flooring may help. Practice will make this a safe and reliable technique. This is the same technique as kiting a Krampus. This pre-bite hit will not cause the horror to teleport.
Then the crawler will ideally try to bite and miss the already dodging player. Hold F to hit the horror again post-bite as explained in the general strategy (link above). This time, hold F longer to "swing twice" (or more) until the horror stops teleporting within melee range.
Done well, this can take down a horror in about 1/3 the time that the general technique requires. This is verified to not work in Hamlet (2023-12-30), even on cobblestones, so probably not in either.