I think it's a phoenix :)
The person that portrayed Albus Dumbledore changed after Harry Potter and the Chamber of Secrets. Richard Harris played Albus Dumbledore for the Philosopher's Stone/Chamber of Secrets, whereas, Michael Gambon has appeared in the Prisoner of Azkaban/Goblet of Fire/Order of the Phoenix/Half-Blood Prince and is set to appear in Harry Potter and the Deathly Hallows.
Albus Dumbledore was portrayed by the late Richard Harris in the second Harry Potter film, Chamber of Secrets. In all subsequent films, he has been replaced by Michael Gambon.
Albus Dumbledore has been played by two actors. Albus Dumbledore was played by Richard Harris in Harry Potter and the Philosopher's Stone and Harry Potter and the Chamber of Secrets. Michael Gambon has played Dumbledore in every other Harry Potter film to date, and is also set to star in Harry Potter and the Deathly Hallows Part I.
Gilderoy Lockhart, a famous author. Note that Harry Potter, Albus Dumbledore, Salazar Slytherin and Lord Voldemort (Tom Riddle) were also mentioned and are famous wizards.
A round character is any character that is developed. So Harry Potter, Ron Weasley, Hermione Granger, Albus Dumbledore and Severus Snape are all examples of round characters.
Albus Dumbledore did.
Ariana Dumbledore.
Albus Dumbledore is male.
In Harry Potter and the Sorcerer's Stone and Harry Potter and the Chamber of Secrets, Albus Dumbledore was played by Richard Harris. Harris passed away from Hodgkin disease during the filming of Harry Potter and the Prisoner of Azkaban, so they had to re-shoot all of his scenes with the recast Michael Gambon, who ultimately played Dumbledore in Prisoner of Azkaban, then in Goblet of Fire, and Order of the Phoenix.
Kenneth Branagh acts as Professor Lockhart.
There are two "Michaels" starring in Harry Potter. The first is Michael Gambon who has starred in all of the films as Albus Dumbledore with the exception of Harry Potter and the Philosopher's Sorcerer's Stone and Harry Potter and the Chamber of Secrets. The second is Michael Wildman who played a centaur in Harry Potter and the Order of the Phoenix.
Albus Dumbledore