Mister Crowley is as bitter a ghoul, who was transformed 10 years ago due to an extreme exposure of radiation that should have killed him. He once lived at Rivet City, but the bias and disdain he experienced there forced him to move on to greener pastures. Crowley discovered Underworld and has taken up permanent residence, but remains resentful of the harsh treatment he received from humans. He presents the Lone Wanderer with a complex revenge plan that he wants the Lone Wanderer to carry out. Mister Crowley spends most of his time in the Ninth Circle, drinking heavily.
Crowley and four other mercenaries - Dave, Jeff Strayer, Dukov, and Tara - were sent to Fort Constantine by Allistair Tenpenny to retrieve a rare weapon. During the mission, Crowley was locked in a room full of feral ghouls by Dukov, who wanted to increase his own share of the payout. Crowley survived the imprisonment and harbors a passionate resentment toward those who left him behind.
If the Lone Wanderer retrieves the keys detailed in Crowley's quest, they can go to Fort Constantine and take the T-51b Power-Armor. Mister Crowley won't be happy however and will only respond with "You stole what was rightfully mine! Get lost.", without an option to give the suit to him. He will say the same thing if the Lone Wanderer pickpockets the keys from him after handing them over.
If the Lone Wanderer hands Crowley the keys and later travels to the Fort Constantine's Bomb Storage section, Crowley will be inside wearing the armor and thank the Lone Wanderer for the keys.
If the Lone Wanderer follows Crowley to Fort Constantine on foot (ie, not by fast travel) Crowley will turn hostile just outside of the fort. If the Lone Wanderer does not engage Crowley, he will turn up back at Underworld wearing the armor.
If the Lone Wanderer kills Crowley at any time, he/she will no longer be able to collect caps for this quest. The Underworld will turn hostile for 72 in-game hours if the Lone Wanderer is detected in this act.
Crowley can die on the way to retrieve the armor, making him hard to find and the armor unobtainable. However, he carries a weapon and healing items which he will use.
Crowley has green hair, which is rarely seen on other characters.
After obtaining the armor, Crowley can appear randomly at places which the player has fast-traveled to or waited at.
Crowley was supposed to have a very high DR perk to make sure he will reach Fort Constantine, but it was removed from the game. Instead, Crowley benefits of a micro-regen perk so if he is not killed outright during a fight he will slowly recover health and get cured of any crippled limb. This perk is granted only during the travel to Fort Constantine.
If the Lone Wanderer tails Crowley to the fort, he will be attacked by super mutants despite several sources saying super mutants don't bother ghouls.
"Or the right money, heh? I've got this list of people. Ghoul bigots. Real scum. I've only got four guys left on the list. Started with eleven. All of them hate Ghouls and treat us like we're zombies. They all deserve to die. But it has to be done with a head shot. Just like the old stories where zombies can only be killed that way. I'll give you 100 caps for each of them. If they die some other way, I'm only paying 25 though."
"Ha, ha! I like a human that knows his place. Too many of you think we're all just zombies. They don't know, or don't care, that we're just as human as they are inside. We bleed! We hurt! We regret! And you know what really pisses me off? They think the only way to kill us is to shoot us in the head, like in the old zombie stories, and that will put us out of our misery. Hey, I know! Maybe you could help me even the score."
"Excellent! Take this sniper rifle, you'll need it. Here's a list of the guys and their last known locations. Word will get around if Tenpenny's killed, but I'll need proof for the others. Bring me back something personal from each of them as proof, like a key, or a ring, or somethin'."
The following is based on unverified behind the scenes information and has not been confirmed by canon sources.
The name Crowley may be based on English occultist, ceremonial magician, poet, painter, novelist and mountaineer Aleister Crowley who founded the religion of Thelema, identifying himself as the prophet entrusted with guiding humanity into the Æon of Horus in the early 20th century.
End of information based on unverified behind the scenes information.
pcxbox360 Occasionally, Crowley will go into a bout of slow-motion sprinting, running at nearly half speed but with full striding animation. He will resume normal movement upon his next combat encounter. [verified]
pcps3xbox360 Crowley may deliver his theft line if the Lone Wanderer acquires the winterized T-51b power armor helmet from the Anchorage simulation, even though it isn't Crowley's actual armor. [verified]
pc With Broken Steel installed: After getting the T-51b power armor and helmet from Fort Constantine by unlocking all the doors, then finishing the You Gotta Shoot 'Em in the Head quest by giving Crowley the keys, and fast traveling back to snatch the armor before Crowley finds out, Crowley has been encountered still friendly in the Presidential metro, just inside the doors from M.A.R.Go.T., during the Who Dares Wins quest. [verified]
xbox360 Occasionally, Mr. Crowley will not appear in the Underworld. [verified]
ps3 If the Lone Wanderer hands over the keys for the reward then pickpockets them back and travels to Fort Constantine to get the T-51b Power-Armor all without killing Mr. Crowley he will disappear from the game. [verified]
ps3 Occasionally Mr. Crowley will exit "Underworld concourse" and won't show up in the "Museum of History Enterance".
xbox360 Sometimes, if the Lone Wanderer completes the quest, Mr. Crowley will repeat his theft phrase and not show up at the fort. Also if the Lone Wanderer steals the keys and tries to get the armor, the game does not recognize that the Lone Wanderer has the keys. Part of the same bug.