Fawkes

Fawkes was a phoenix that was owned by Albus Dumbledore. Fawkes lived with Dumbledore at Hogwarts Castle for a large part of his life. He was instrumental in helping Harry Potter defeat Slytherin's Basilisk. He was also used as a communication between his master and the Order of the Phoenix. Fawkes assisted Dumbledore fighting Lord Voldemort. When Dumbledore died, Fawkes left the castle and was never seen again.

Early Life
Much of Fawkes' origins are unknown, but before being tamed by Dumbledore, two of his tail-feathers were procured by the wand maker Ollivander, and fashioned into the cores of two wands (a rare event, as should the two meet, it would initiate Priori Incantatem), made from yew and holly. The yew wand went to Lord Voldemort and the holly went to Harry Potter.

Service to Dumbledore
Fawkes was tamed and owned by the famed wizard Dumbledore, and served him faithfully for many years.

As part of his efforts to help Harry in his quest to defeat and kill the Dark Wizard Voldemort and his followers, Dumbledore called Fawkes into battle whenever needed. Throughout the years, there were several instances where Fawkes was extremely helpful.

1993
In 1993 where Fawkes came to Harry's aid, saving his life from Slytherin's Basilisk by pecking it's eyes out and dropping the Sorting Hat into Harry's lap, which in turn revealed Godric Gryffindor's Sword, and then shed healing tears upon Harry's wounds, inflicted by the Basilisk before it's death, and cured him of it's venom. He then dropped Tom Riddle's diary into Harry's lap, giving him the chance to destroy it.

1995
In late 1995 where Fawkes served as a communication between members of the Order and Dumbledore after learning Arthur Weasley had been attacked by Voldemort's pet serpeant Nagini while guarding the The Prophecy. Fawkes's involement was instrumental in saving Arthur's life.

1996
In later 1996 where Fawkes came to his master's aid, swallowing a Killing Curse intended for Dumbledore, thus giving the headmaster time to defend himself. He exploded the second he swallowed it, though was reborn and returned to the sanctuary of Dumbledore's office following his departure from the Ministry of Magic.

Departure
When Dumbledore died in 1997 after the Battle of the Lightning-Struck Tower, Fawkes, due to his deep emotional bond he had with his master as a result of being claimed by him upon re-birth, was devastated, and sang his Phoenix Lament to the assembled mourners, severely affecting all with its beauty. Fawkes left Hogwarts forevermore, becoming a wild phoenix; which has no ties to any human, though not before dropping by the funeral of his master; and conjured a source of flame which engulfed Dumbledore's body at his funeral, and reformed into the White Tomb.

Personality
Fawkes served as Dumbledore's messenger (a duty normally left to Owls), and his constant companion and pet. Whenever Fawkes died and was re-born, Dumbledore was always there to claim him, and as such a deep emotional bond formed between him and his master. Fawkes was also affiliated to Harry and his friends, family and their respective allies, serving as a beacon of strength and power during the dark years of the Second Wizarding War, with Fawkes also serving as inspiration for the naming of the Order of the Phoenix, which Dumbledore founded to fight off Voldemort and his Death Eaters. When Fawkes departed, he left a deep emotional void behind.

Abilities
Being a phoenix, Fawkes periodically dies by bursting into flames (an event called a "Burning Day"), and is then reborn from the ashes. Fawkes also possesses several other remarkable powers; his healing tears, his ability to carry heavy weight with remarkable grace and strength, and also can teleport at will, regardless of the anti-Apparation enchantments surrounding the school. Fawkes also possessed remarkable and soul-touching singing talents.

Name etymology
Fawkes' name is supposedly derived from the name "Guy Fawkes". A somewhat humorous and subtle hint at this origin is present in the first book, where fireworks shot off in celebration of Voldemort's apparent defeat are attributed to an early celebration of Bonfire Night (Guy Fawkes' Day) by a muggle news reporter.