Aragog was from a distant land, where a traveller had found him and eventually given to Rubeus Hagrid as an egg. Aragog was raised in the dungeons of Hogwarts Castle. However, he was banished to the Forbidden Forest and was accused of being the monster that killed Myrtle Warren. Hagrid eventually found Aragog a mate, Mosag, as they had many sons and daughters.
The Chamber of Secrets
Aragog is visited by Harry Potter and Ronald Weasley after Hagrid is taken to Azkaban by Cornelius Fudge. Looking for answers, the boys inform Aragog of what happened with Hagrid and that the Chamber of Secrets has been opened again. Aragog clarified that Hagrid did no such thing and he was not the monster who has petrified the students, in the present and fifty years ago. When they ask of what creature is responsible, Aragog yells that they do not speak of the creature (the Basilisk. He then begins to let his children attack Harry and Ron, but luckily, the boys make their escape.
- Harry Potter and the Chamber of Secrets (First appearance)
- Harry Potter and the Order of the Phoenix (Mentioned only)
- Harry Potter and the Half-Blood Prince (Appears as a corpse)