When Cordelia is browsing the demon database, Wesley asks her if they have "the Vigories of Oden Tal." This is a reference to the main antagonists of She (2000).
When Cordelia and Wesley are trying to find a way into the illegal demon fighting gladiator arena to save Angel, they stop a couple that's about to enter and, in an effort to acquire their tickets, Cordelia states "I'm Detective Andrews, this is Detective Yelsew...". Yelsew is actually Wesley spelled backwards.
The character of Tom Cribb is based on the boxer Tom Cribb (1781-1848), who was one of England's most celebrated champions of the bare knuckle era. He made "milling on the retreat" acceptable as a mode of fighting. He held the title throughout the years of the sport's peak in popularity. Upon his retirement in 1822, he was awarded a lion-skin championship belt, the first "title belt".
Actor Markus Redmond (Tom Cribb) also played Griff in Angel: Rm w/a Vu. When Angel wakes up after being captured, he looks around his cell and jokes "I asked for a room with a view."
This episode marks the first appearance of Lilah Morgan, who would be a recurring character for the next three seasons.