While Ella Mental, Rubber Chucky and Indestructi-Bob came back with Eradicus, Mel-licular didn't return since Welcome to the Dark Tomorrow. He was written off the show for unknown reasons.
Miss Millipede from Yin, Yang, Yuck!, the multi-eyed monster from Scary, Scary, Quite Contrary, and Carl's Friend from Pro's and Con's, all have non-speaking cameo appearances in this episode.
List of fears the characters have:
1) Master Yo - high cholesterol
2) Dave - bad jokes and termites
3) Roger the Skelewog - his own wife
4) IndestructiBob and Rubber Chucky - the first day of school
5) Yang - nothing
Running gags in this episode: 1. Yang refuses to be scared of anything he sees that is usually considered to be scary. 2. Yin tries to come up with a scary costume idea, and keeps failing until she faces the Howl-Weenie. 3. Eradicus keeps blasting his minions when they say something stupid or don't know what Eradicus is talking about. 4. Master Yo keeps trying to get free candy, and usually fails. 5. After the town citizens lose their fear, they refuse to run away from the Howl-Weenie.
After Coop loses his fear, he kisses Yin for the first time in the series!
Lena: Look Yang, I'm sorry if you're too cool for the room...
Yang: Apology accepted.
Lena: But it's Weenie Howl, and the rest of us want to have a good old scary time.
Yang: So do I! Will you wake me when it starts?!
Lena: You can stay here and be grumpy...
Yang: Really? I thought you were done.
Lena: Or you can come out to the Boogeyman's annual Weenie Howl funk party, and possibly hold my hand on the dance floor.
Yang: (sighs) Consider me bribed. Heck, disco music is pretty scary.
Eradicus: (walking back and forth) So my minions, do you know why I've summoned you all here?
IndestructiBob : To tell us you're really a parrot?
Eradicus: (surprised and a bit unsure) Seriously, do I scream "Polly want a cracker," to you?
Rubber Chucky: No, No.
Ella Mental: No, not at all.
IndestructiBob: But neither did my cat, Mr. Featherbeak. It took us all by surprise. (Eradicus zaps IndestructiBob)
Lena: I'm officially fearless so I can say this, I think you're cute but your ears are dopey.
(Eradicus rampages through town, only to see nobody running away)
Eradicus: What's going on? No one's scared.
Ella Mental: Well, duh. We sucked it out of them. That was the plan remember? (angrily, Eradicus zaps Ella)
Ella: I'm getting tired of that.
Yin: Isn't anyone feeling scared of me?!
Coop romantically: I'm feeling something for you if that makes you feel any better.
Ella Mental: Eradicus, you still haven't told us. How do we bring the Weenie-Howl back to life? (Eradicus zaps her) With all due respect, that was a fair question.
Yang: Yin, will you stop clowning around?! I want more scares and less jokes!
Yin: Why? I haven't heard of one joke here yet!
Dave: You better put me down! My friends will come to rescue me!
Rubber Chucky: No, they won't.
Dave depressed: You're right, they won't.
This episode was made available for viewing online at Disney Channel's official website before it made it's TV premiere.
Despite what it looked like in Welcome To The Dark Tomorrow, Eradicus is still alive and the Night Master lineage could still possibly continue.
Yin: Oh, no! He only plumps up when we try to cook him! This line is the famous slogan for Ball Park Franks.
Trick Or Treat: Master Yo goes Brick Or Eating, a parody of the famous Halloween tradition.
Thanksgiving: Yang mentioned the holiday of Givethanksing, which is an obvious parody of the holiday that comes in November.
Halloween: The holiday of Weeniehowl is parody of the holiday that comes every October 31st.
Yang: I think there must be something wrong with me Yin. Weenie-Howl is here, but I'm not scared. I just don't feel the way I'm supposed to feel.
This quote that Yang says is very similar to what Charlie Brown says in the 1964 animated T.V. special, A Charlie Brown Christmas, only Charlie Brown talked about not feeling happy for the Christmas holiday instead of Yang's holiday.
Seinfeld: When Eradicus is doing his stand-up joke, a musical rift from the long-running T.V. series plays to punctuate the fact that Eradicus is trying to be funny even though he actually isn't.
A Christmas Carol: When Master Yo sees Yang covered in yellow goop, Yo thinks Yang is the Ghost of Cholesterol Future, and promises to change his bad-eating habits so the Ghost will stop haunting him, and so Yo will have a better future. It's similar to what happens towards the end of the Charles Dicken's masterpiece, where Ebenezer Scrooge sees the Ghost of Christmas Future, learns the possible consequences of not changing his greedy habits, then promises he will change so the ghost will stop haunting him.
Captain Planet and the Planeteers: The idea of the Howl-Weenie being created and growing stronger from fear, and the fact that it could only be defeated by the opposite of fear which was cuteness, is similar to the rebirth of Captain Pollution in the multi-parter episode A Mine Is a Terrible Thing to Waste. Captain Pollution was created from pollution, grew stronger from more pollution, and was only defeated by the opposite of pollution, a natural element of the Earth.
Betty Boop: When the Weenie-Howl song starts playing, the words appearing on-screen and having a bouncing ball jump on the words as they're being sung, is very similar to what was done in many segments of this old Fleischer/ Paramount cartoon shorts that appeared from 1929-1939.