Behind the scenes In a chat with fans on the-leaky-cauldron.org, J. K. Rowling answered a fan's question of why Albus Dumbledore was sometimes able to see Harry under the Cloak of Invisibility, explaining that he used the Human-presence-revealing spell with non-verbal magic.
Why can mad eye moody see through the Invisibility Cloak?
A fake eye belonging to Alastor 'Mad-Eye' Moody, the enchanted device had an electric blue iris and could rotate 360 degrees in the wearer's head. The eye was able to see through anything, including the back of Moody's own head and even invisibility cloaks, and was the reason that Moody became known as 'Mad-Eye.
Did Dumbledore know the cloak was a deathly hallow?
Dumbledore was very interested in the Deathly Hallows, and he suspected James Potter's Invisibility Cloak might be one of these artifacts, which he confirmed while the Cloak was in his possession.
Both Albus Dumbledore and Voldemort were aware of this ancient magic, and Voldemort was known to "despise" it. indeed, Dumbledore was able to willingly invoke a form of ancient magic, a bond of blood charm, to protect Harry Potter so long as he was in the Dursley family's care.
The REAL Reason Dumbledore Borrowed the Cloak of Invisibility - Harry Potter Theory
How did Harry Potter's dad get the Invisibility Cloak?
To elaborate on Icecreamdif's answer, he inherited it as a family heirloom dating back to Hardwin Potter, who married Iolanthe Peverell, granddaughter of the Cloak's original owner Ignotus. It was passed down to the eldest male of each new generation of Potters since then.
Snape definitely knew because in book 4 when Harry sees crouch in Snapes office, he's in his invisibility cloak. As soon as snape sees the golden egg and the map he says 'potters here' to mad eye. Potters here. This is his egg and he's in his invisibility cloak.
Wandless magic could also be performed nonverbally, but this increased the level of difficulty to the point that only practitioners of exceptional skill could perform more than the most basic magic. Albus Dumbledore, generally considered the greatest wizard of all time, was known for performing magic in this manner.
The term Muggle is sometimes used in a pejorative manner in the novels. Since Muggle refers to a person who is a member of the non-magical community, Muggles are simply ordinary human beings without any magical abilities and almost always with no awareness of the existence of magic.
Wizards and witches hid their world with Muggle-Repelling Charms, and if a Muggle witnessed a magical event or saw a magical creature such as a dragon, their memories were erased. Confundus Charms were also occasionally employed to encourage Muggles to ignore any magic they witnessed.
Dumbledore knew about Horcruxes. He knew how they were formed, what happened after that, etc. He probably got to know Harry was a Horcrux when he saw the Scar on Harry's forehead, but maybe he wasn't sure.
While in school together, Sirius once tricked Snape into almost entering the Shrieking Shack while Lupin was there, transformed into a werewolf. James realised the danger and stopped Snape, saving his life; this is the incident Dumbledore referred to at the end of the first book.
Albus Dumbledore, arguably one of the greatest wizards in history, has been the only wizard recorded who didn't inherit the Parseltongue ability but could understand it. It is unclear how he was able to learn it, however, although he could understand it and imitate some sentences, he was not fully able to speak it.
In July 1997, Moody was killed by Lord Voldemort during the Battle of the Seven Potters. Moody's corpse was recovered by the Death Eaters, and his magical eye was somehow taken by Dolores Umbridge, who used it to keep track of her subordinates in the British Ministry of Magic.
Can Mrs Norris see through the Invisibility Cloak?
Harry had the suspicion that she was able to see him even when he was under his Invisibility Cloak, although she may have just sensed someone there but couldn't see, as cats are known to possess highly advanced senses that humans do not have.
At different points, Dumbledore possessed all three Deathly Hallows. He won the Elder Wand from Grindelwald, had the Invisibility Cloak in his possession when James Potter died, and wore the Resurrection Stone as it sat in Marvolo Gaunt's ring.
She and her husband were proud and accepting of their daughter's identity as a witch, which explained some strange things which happened around her when she was a child. They entered the magical world in 1992 to buy Hermione's school supplies, and were assisted by Arthur Weasley.
Hogwarts Castle appears as abandoned ruins to any Muggles close enough to see. Although wizarding society lives for the most part directly alongside Muggles, the interaction between the two communities is virtually non-existent since the International Statute of Wizarding Secrecy was introduced in 1692.
"In the Harry Potter universe, wands are an innately magical tool, capable of rebelling against their user or switching loyalties (such as the Elder Wand). A Muggle gaining one wouldn't just effectively have a stick in their hand but could produce an uncontrollable magical effect."
It's never explicitly mentioned, but it's possible that Draco Malfoy can perform wandless magic. After spotting an invisible Harry in his compartment, Draco shuts the door and closes the blinds to block out sight so he can confront Harry.
as long as we're in a fantasy world, all answers are equally valid (or invalid, according to your preferences): muggles don't have magical power. That's a Potterverse axiom … “the wand chooses the wizard,” also a given. Why would a wand choose a non-wizardly muggle?
He promised to protect Draco Malfoy from harm and guide him whilst he attempted to perform the task the Dark Lord had asked him to do: to kill Albus Dumbledore. Snape was actually a double agent working for Dumbledore, who requested Snape to kill him anyway to spare him of a painful and humiliating death.
How did Draco know Harry was under the invisibility cloak?
From his confrontation with Harry in PofA near the Shrieking Shack. Malfoy saw Harry's head during the fight and most likely deduced he was under an invisibility cloak that slipped and showed his head.
Harry did possess each of the Hallows eventually, for a brief moment of time. Without realising it, Harry Potter possessed one of the Hallows from the age of 11, the Cloak of Invisibility. The Cloak was rightfully his, and should have been passed down to him from his father, James Potter, had he not been murdered.
