Castiel is the Angel who rescued Dean from Hell, according to Castiel on a command from God. His handprint is burnt into Dean's arm.
His true voice is piercing to the human ear and only certain people can hear him properly this way or so he claims, and looking on his true visage will burn a human's eyes from their head, as Pamela Barnes found when she tried to summon him in a seance. It will also burn the eyes of humans possessed by demons as shown in the diner scene when Sam is attacked by a blind demon. When he meets Dean he is inside the body of a man he says "prayed for it".
Misha Collins who plays Castiel reports that "Kripke wanted to base the look of the character on the comic book character ‘Constantine’".
Castiel is an Angel Of Thursday in occult lore. This may be a reference to the fact that Supernatural airs on a Thursday night on The CW.
Episode Appearances (Season 4): (Click on the episode title to learn more)
• Are You There God? It's Me, Dean Winchester
• In The Beginning
• It's the Great Pumpkin, Sam Winchester
• I Know What You Did Last Summer
• Heaven and Hell
• Death Takes a Holiday
• On the Head of a Pin
• The Monster At the End of This Book
• The Rapture
• When the Levee Breaks
• Lucifer Rising
Episode Appearances (Season 5): (Click on the episode title to learn more)
• Sympathy For the Devil
• Good God Ya'll
• Free to Be You and Me
• The End
• I Believe the Children Are Our Future
• Changing Channels
• Abandon All Hope
Memorable Quotes:
• “I’m the one who gripped you tight and raised you from perdition.”
• “You should show me some respect. I dragged you out of Hell. I can throw you back in.”
• “They’re all my Father’s creations. They’re works of art.”
• “I’m not a hammer as you say. I have questions. I have doubts.”
• “I don’t envy the weight that’s on your shoulders, Dean. I truly don’t.”
• “I’m considering disobedience.”
