Reaching Serpent's Peak/Defeating the Fire Viper on the inside and outside

Here is how the fight with the Fire Viper begins in Return of the SWAP Force.

As for the Fire Viper, he was getting closer to the Skylanders and the heroes.

Flynn: Hey! Lookie there, he's free!

Sharpfin: She's free, the Ancient Terrasquid is a girl!

Flynn: Really? Oh, that's a woman?

Sharpfin: (chuckles) Ya know what, Flynn, you're alright! I tell ya what, why don't you take the wheel?

Flynn: You mean it!? (hopped right into Sharpfin's ship) Let's do it! (took off)

Sharpfin: Oy, Flynn! Aren't you forgetting something!?

Just as they watch Flynn taking of without them, the Fire Viper was coming up from behind them.

Sharpfin: Oh, right. Ya see here? This isn't good.