Wrong house

This stage direction is from the script for Expecting, in the scene in which Angel and Wesley get the wrong house whilst demon-hunting:

Wesley charges in, startling an ELDERLY COUPLE watching TV. Angel charges in behind him, SMACK! right into the ‘No Uninvited Vampires Allowed’ threshold.

Howard Gordon

Howard Gordon co-wrote the episode What’s My Line? (Part 1) with Marti Noxon, and was consulting producer on the show. He was also a consulting producer and writer on Angel. He wrote the Angel episodes ‘Hero’, ‘Expecting‘ and ‘The Ring‘. Howard worked with Buffy’s executive producer David Greenwalt before, on an episode of The X-Files. He wrote many episodes and was co-executive producer of both 24 and The X-Files.

Wilson Christopher

Wilson Christopher was a photographer whose group of friends acted as surrogates to impregnate women with the seed of their master, a Haxil demon. In exchange for doing this they received fame, wealth and success. Cordelia began dating Wilson, and woke up heavily pregnant after sleeping with him for the first time. Angel tracked him down to a gun club, where a huge fight between Wilson and his friends ensued. Wilson was not killed, but Wesley and Angel destroyed the Haxil demon, making further pregnancies impossible.

Blood drinkers

Both Cordelia and Wesley have drunk blood on Angel - Cordelia drinks Angel’s blood supply from his fridge in Expecting and Wesley is offered blood when pretending to be Angel in Guise Will Be Guise.

Haxil Beast

The Haxil Beast (latin name: ‘Haxil Daemonica’) offers wealth, fame and success to human men to impregnat human women with it’s spawn. It then telepathically controls the women via it’s link to it’s unborn children. The gestation period is very short and the women give birth very quickly. The Haxil Beast is huge, speaks English and neither decapitation nor fire will kill it. It was destroyed in Expecting when Angel threw a liquid nitrogen canister at it, which Wesley shot. Cordelia shattered the beast in revenge for impregnating her.

Evita

In Nightmares, Willow says, “Why is she so Evita-like?” Evita was the nickname of María Eva Duarte de Peron (1919-1952), an Argentinean actress who married political leader Juan Peron. She gained a massive political following as an outspoken champion of women and the poor. Andrew Lloyd Webber wrote a musical based on Eva Peron’s life, called Evita. It was turned into a 1996 movie starring Madonna and Antonio Banderas.
In Expecting, Cordy says to her ghost, “Alright Dennis, knock it off! This is the first guy I’ve actually liked in a long time, and if you keep killing the mood I’ll kill you - all right, empty threat, you being a ghost, but I’ll do something worse… I’ll play Evita around the clock… the one with Madonna!”

Seen at 28.14 minutes:

When we see Cordy drink Angel’s blood suppy in Expecting, she drips blood down the front of herself but later, when see her hit Wesley with the book, there is no blood there.