Houndoom is a quadruped, canine Pokémon that is mainly colored black with a long orange snout and an orange underbelly. It has small, red eyes and a black nose. Around its neck is a white band with a small skull-shaped pendant on its throat. There are two white bands on each of its ankles, as well as three rib-like ridges on its back. Houndoom has a long, skinny tail with a triangular tip and three clawed toes on each paw. On top of its head is a pair of long, curved gray horns. These horns are smaller on the female than the male.
In a Houndoom pack, the one with its horns raked sharply towards the back serves a leadership role. Leadership is determined by fights within the pack. Its gut is full of toxins, which are used to create unique fire mixed with poison. This gives Houndoom's fire a foul odor and the wounds it inflicts will never heal. After finishing off the prey, Houndoom divides it evenly among its pack. Houndoom appears near rough terrain areas. Its howling induces shivering in other Pokémon, and often sends them scurrying back to their nests. This resulted in people referring to Houndoom's howl as the Grim Reaper.
As Mega Houndoom, the ridges on its back thicken, and it gains additional, bone-like rings around the base of its tail. The rings on its tail have small spikes on top, causing them to resemble vertebrae. The ridge at the base of Mega Houndoom's neck is longer and curves forward towards its shoulders. Instead of a band with a skull pendant, there is a large, toothed structure around its neck. This bone-like formation has two large spikes on either side and three pointed teeth on the bottom. Mega Houndoom's horns now point straight up with a small, outward curve in the middle. The two bands on its hind legs have vanished, and those on its forelegs are broken in the front. Its claws are a dark red due to its ability to generate more heat, which themselves cause pain to Mega Houndoom.[1] Finally, the tip of its tail is now split down the middle. When it Mega Evolves, its entire body generates heat. Its fiery breath is not powerful enough to burn foes into ashes.
In The Power of Us, a Pokémon hunter's Houndoom and another hunter's Sneasel searched for Zeraora, but targeted a Teddiursa and Ditto instead. This forced Zeraora and soon Ash and his friends to intervene, eventually leaving Sneasel defeated.
In Lucario and the Mystery of Mew, multiple Houndoom were part of the feuding armies that were eventually placated by Sir Aaron in the past. Three of them attacked Lucario just before.
In the Pocket Monsters HGSS Jō's Big Adventure manga
A Houndoom appeared in JBA4, under the ownership of Archer.
In the Pokémon Adventures manga
A group of Houndoom first appeared in Slick Slowking, used by Carl to prevent Gold and Crystal from attacking with their Roar attack.
Maxie has five Houndoom in his arsenal, one of which he used to kill Norman to prevent him from using Rayquaza to interrupt Kyogre and Groudon's fight again. They first appeared in It All Ends Now V.
In a Houndoom pack, the one with its horns raked sharply towards the back serves a leadership role. These Pokémon choose their leader by fighting amongst themselves.
In a Houndoom pack, the one with its horns raked sharply toward the back serves a leadership role. These Pokémon choose their leader by fighting among themselves.
Houndoom has three different sprites in each Generation II game. It also shares this same trait in Generation IV games. This makes it one of the few Pokémon with this distinction.
Origin
Houndoom may have been based on the Cerberus of Greek and Roman mythology, or other legends of hellhounds. Houndoom is also similar in appearance to Dobermanns. Its tail resembles that of common depictions of the devil. Houndoom also seems to bear some resemblance to the extinct thylacine, a hound-like marsupial with a lean body and stripey pattern on its back, much like Houndoom in respects of appearance. Houndoom's Shiny coloration could be based on Yama, the Hindu Lord of the Fallen, who often appears blue and red. Its pack-hunting, social nature, pecking order, and overall feral nature may be a reference to gray wolves.