Cerberus
Cerberus, a three headed demon dog, was guardian of the Underworld. The creature prevented souls from leaving the realm. He is often depicted as having 3 heads, although in most stories he has two. He also has some sort of snake somewhere on him, some stories say it's his head that has snakes, others say his tail is multiple venomous ones.
Family
Cerberus was a part of a whole family of creatures with an abnormal amount of heads. His three brothers were just as intimidating as he was. On the top left is Othrus, another dog-like creature, and is the only one who bares similarity to Cerberus. The top right is a picture of the Chimera, a monster with the head of a lion, dragon, and goat. The Chimera had dragon wings, and a serpent's tail. On the bottom is the Lernaean Hydra, who of course, is a hydra. These multi headed creatures came from Typhon. Much like the Chimera, Typhon looks like many creatures were superglued together, like Frankenstein's monster. Their mother was Echidna, half snake, half woman. She is referred to as the mother of monsters.
Guard Dog
Cerberus would act like a normal, playful dog when meeting a new soul going into the underworld. When a soul exempted to escape, Cerberus killed and ate them, showing to others that they must remain there forever.
12th Labor
Hercules 12th labor required him to bring Cerberus to King Eurystheus. When he entered, he asked Hades to borrow his dog. Hades said that he could borrow Cerberus only if he could make the dog submit without weapons. So their fight began. A snake on Cerberus's tail bit Hercules. So, Hercules strangled the snakes, but only until they submitted. Hercules bound the dog in chains and returned to the king. The king regretted demanding to have Cerberus and immediately ran away. Hercules, being a kind demigod, released the dog. Cerberus returned to his post at Hades, continuing to be an amazing guard dog. There are several ways this story was told. Some say that Hercules fought Hades instead of being polite and just asking.
Venom
The beast had more than just razor sharp teeth, sharpened claws, and snakes as a body part, he had venom. His spit contained the deadly poison, and when he drooled, the slobber that fell to the ground turned into a flower. Despite being a pretty, purple plant, it is very poisonous. It's often called wolfsbane.
Name Origin
The name Cerberus's origin is debated. One theory is that word Cerberus comes from the Proto-Indo-European word kerberos, which turned into Cerberus when it went from Greek to Latin. The word Kerberos means "spotted." Yes, the demonic dog of the underworld, is named spot. This admittedly makes him much less intimidating, and makes him seem a bit like a normal dog.
Constellation
There is a constellation with Cerberus, although he is depicted as a three headed snake instead of a dog. He is being strangled by Hercules, and being forcefully dragged out of the underworld. This constellation was introduced by Johannes Hevelius in 1687. Cerberus was made of four stars, now known as 93, 95, 102, and 109.
Conclusion
In conclusion, Cerberus doesn't seem like that much of a monster. He enjoyed greeting new souls, and was the guard dog of the underworld. His name was "Spot," one of the friendliest names a dog can have. When Hercules released him, he ran back to his master. He's just a loyal, friendly, protective pooch.
