When Ozai tells Azula that his decision is final, the gold lining on his outfit is red.
When Katara and Suki push apart the crowd, Katara's hair is missing from between her hair strips and neck, showing the background instead of hair.
When Katara and Suki are looking for Aang, they see the actors playing Aang and Toph from the play in The Ember Island Players.
Toph: ... And then when I was nine, I ran away again.
Zuko: (nonchalantly) Uh-huh
Toph: I know I shouldn't complain. My parents gave me everything I asked for. But they never gave me the one thing I really wanted: their love. You know what I mean?
Zuko: (sighs) Look, I know you had a rough childhood, but we should really focus on finding Aang. (continues walking)
Toph: (stops) This is the worst fieldtrip ever...
Toph: Err... what about me?
Sokka: For now, you're the Melon Lord's forces.
Toph: So I get to chuck flaming rocks at all of you.
Sokka: Whatever makes the training feel more realistic.
Zuko:There's one technique you need to know before facing my Father. How to redirect lightning. (Aang grins with anticipation) If you let the energy in your own body flow,(Zuko traces out a path through his body to the show the path of the energy flow) the lightning will follow it. You turn your opponent's energy against them.
(Aang waking up on the lion turtle)
Aang: I just had the strangest dream. (pause) Wait, where are we?
Zuko: My whole life I struggled to gain my fathers love and acceptance, but once I got there, I realized I lost myself getting there. I had forgotten who I was.
Zuko: If you want to lounge around like a bunch of snail sloths all day then go ahead.
Sokka: Maybe Zuko's right, sitting around the house has made us pretty lazy... but I know just the thing to change that. (jumps up and tears off his robe revealing a swim suit) Beach party!
Zuko: The people of the Earth Kingdom are proud and strong; they can endure anything as long as they have hope.
Katara: Who wants a nice cold glass of watermelon juice?
Aang: Ooh, ooh, me! Me! Me!
Toph: I'm not Toph! I am Melon Lord! Mwa ha ha ha!
Sokka: Team Avatar is back! (zoom to Aang) Air! (zoom to Katara) Water! (zoom to Toph) Earth! (zoom to Zuko) Fire! (zoom to him and Suki) Fan and sword!
Aang (trying to find a way to stop Ozai without killing him): Maybe we could make some big pots of glue, and then I could use Glue Bending to stick his arms and legs together so he can't bend anymore.
Zuko (sarcastically): Yeah, then you could show him his baby pictures, and all those happy memories will make him good again.
Aang (sincerely): Do you really think that would work?
Aang (about killing the Fire Lord): This goes against everything I learned from the monks. I can't just go around wiping out people I don't like!
Sokka: Sure you can. You're the Avatar.
Katara: I was looking for cooking pots in the attic, and I found this. (unrolls a portrait of a baby boy) Look at baby Zuko! Isn't he cute? (everyone laughs except Zuko) Oh, lighten up, I'm just teasing.
Zuko: That's not me. It's my father.
Zuko: What's wrong with all of you? How can you sit around having beach parties when Sozin's Comet is only three days away?
Katara: What should we do, Zuko?
Zuko: I don't know. Why are you all looking at me?
Katara: Well, you're kind of the expert on tracking Aang.
Toph: Yeah. If anyone's got experience hunting the Avatar, it's you.
Toph: Hey wait a minute. Has anyone noticed that Momo is missing too?
Sokka: Oh no! I knew it was only a matter of time! Appa ate Momo! (opens Appa's mouth and looks in) Momo, I'm coming for ya, buddy!
Katara: Sokka, Appa didn't eat Momo. He's probably with Aang.
Sokka: That's just what Appa wants you to think! (climbs into Appa's mouh)
Zuko: Get out of the bison's mouth, Sokka! We have a real problem here.
Katara: Get over here, Zuko. Being part of the group, also means being part of group hugs.
Aang: Get a grip before I blast you off this roof!
Zuko: Go ahead and do it.
Katara: What happened?
Sokka: Zuko's gone crazy! I made a sand sculpture of Suki and he destroyed it!
Sokka: Oh, and he's attacking Aang.
(Aang and Toph walk up to Sokkas sand sculpture)
Aang: Is that a blubbering blob monster?
Sokka: No, it's Suki!
(discussing Aang's mysterious disappearance)
Katara: Then he's got to be somewhere on Ember Island. Let's split up and look for him.
Toph (zooms over and clings to Zuko's arm): I'm going with Zuko! (Everyone stares at her and Zuko blushes) What? Everyone else went on a life-changing field trip with Zuko. Now it's my turn!
Fire Lord Ozai (To Azula): And for your loyalty, I've decided to declare you the new Fire Lord.
Azula: Fire Lord Azula, it does seem appropriate.
This episode aired along with "Sozin's Comet (2): The Old Masters", "Sozin's Comet (3): Into the Inferno", and "Sozin's Comet (4): "Avatar Aang" as the TV-Movie/Series Finale: Sozin's Comet: The Final Battle.
The plot for this episode, along with the other three parts of the finale, was revealed a few months before the episode aired in a children's book called Sozin's Comet: The Final Battle.
This episode is available in the Book 3: Fire, Volume 4 DVD, along with, "The Southern Raiders", "The Ember Island Players", "Sozin's Comet (2): The Old Masters", "Sozin's Comet (3): Into the Inferno", and "Sozin's Comet (4): Avatar Aang".
When the gang is at the bar, one of the people seen getting beat up looks exactly like Ryu from Street Fighter, which some of the moves in Avatar are based of.
The scene where Ozai was crowned Phoenix King greatly resembled one of Adolf Hitler's Nazi rallies.
In Greek mythology, the phoenix is often associated with fire, in addition to being a symbol of rebirth and divinity.