Teenage Mutant Ninja Turtles, Season 4

Raph:
I'm tired of training with kid gloves. No one's pulling punches out there. Why should we do it in here? (Pushes Leo away)

Leo:
Raph!

Splinter:
Teishi, because you are brothers and your goal here is to train.

Raph:
(groans) Sensei, why do you always stick up for Leo? I'm the only one who takes training seriously. The rest of 'em are just goofing off all the time.

(Raph throws a ninja star at Donnie's juice container)

Donnie:
(mimics) "No one appreciates me." Back on the "Everyone loves Leo" routine? Get some new material, you big baby.

Mikey:
(Laughs)

Raph That's it! If you guys don't want to take this as seriously as I do, then I quit! I'm done! Through! Adios!

(Raph storms out of the lair)

Leo:
How many times has he quit the team now?

Donnie:
Twenty-seven times.

Splinter:
You have a brilliant mind, Donatello. Yet you see a fire and try to put it out with gasoline. You are growing up, my sons, and you must become more mature. One day I will not be around to remind you of your foibles.

Michelangelo:
Is foible that dangly thing that hangs at the back of my throat?

Donatello:
Foible means "weakness of character," shell brain!

Leonardo:
Master, you've made it through the worst of the worst. And we're never gonna let-

Splinter:
Everything isn't permanent, Leonardo. You cannot expect anything to last forever, even...family.