- [Season One Theme Song]
- Bad City: Our world's about to break/Tormented and attacked/Lost from when we wake/With no way to go back/I'm standing on my own/But now I'm not alone/Avengers, assemble!/Always, we will fight as one/Until the battle's won/With evil on the run/We never come undone/Assemble, we are strong/Forever fight as one/Assemble, we are strong/Forever fight as one.
- [Season Two Narration]
- Nick Fury: And there came a day unlike any other, when Earth's mightiest heroes found themselves united against a common threat. On that day, they became The Avengers. The invincible armored Iron Man. Thor, prince of thunder. The Hulk, strongest hero there is. And, Captain America, the first Avenger.
- Bad City: [singing] Assemble, we are strong/Forever fight as one/Avengers, assemble!