This is a cartoon show which has been my favourite since a kiddo!:P
They are singing 'macademia nut' not 'macarena', but yep, its the macarena tune! Classic comedy songs, and damn original!
But yeaaa, this vid is one of the few songs animaniacs sang, quite catchy, enjoy!:P

lyrics for macademia nut:)

(Dot laughs)
Y+W : Helloooo, nurse!
Yakko : Uhhh...
Dot : (spoken) I am NOT trying to be annoying.
Y+W : Aie!

Dot : I act like a nut, so they call me Macadamia
I dance like a klutz on a show called Animania
Dot overdub: Am I a cutie?
Absolutey!
And a beauty, you can bet your patootie!
D+N+Minerva: But if you touch me, or even get near me
I'll have you arrested, do you hear me?

Y+W : Dot is a nut, so they call her Macadamia
She's cracked in the head, and kooky in the brainia
Each line in this song sounds pretty much the sameia
Oy, Macadamia!
Ralph : Daaah...
Y+W : Donde que vas a Nintendo Macadamia
Hola que pasa you grande sack o' grania
Qui a coupé le fromage, we abstainia
Oy, Macadamia!
(Wakko burps)

Dot : Now, please don't mention my brother
The one they call Wakkoreno
(Wakko burps)
Dot overdub: He's always burping
Every hour
Dot : So I threw him out of the tower.

Wakko : Whoooaaaaaa!
(Dot laughs)
Dot : (spoken) Now come on, what did you want me to do?
He was grossing me out!
And I'm just a cute little thing.
So don't cross me!

Y+W : She's cracked like a nut, so they call her Macadamia
Whenever she gets mad, you'll experience painia
Cuts and bruises you will sustainia
Oy, Macadamia!
Pinky : Narf!
Y+W : Lava tus manos, por favor, Macadamia
The world is the goal for Pinky and the Brainia
Dot : Otra vez on y vas the repetitive refrainia
Y+W : Oy, Macadamia!
Brain : Ye-e-ess!!!

Dot : (spoken) Don't hate me because I'm cute.

(Pesto beats up Squit)
Squit : Ow!

Yakko : Mac, Mac Mac, Mac, Mac, Macadamia
Mac, Mac Mac, Mac, Mac, Macadamia
Mac, Mac Mac, Mac, Mac, Macadamia
Oy, Macadamia!
Skippy : Spew!
Yakko : Mac, Mac Mac, Mac, Mac, Macadamia
Mac, Mac Mac, Mac, Mac, Macadamia
Mac, Mac Mac, Mac, Mac, Macadamia
Y+W : Oy, Macadamia!
Boo : B'gawk!

(Dot laughs)
(Skippy laughs)
(Pinky laughs)
(D+Sk+P+HN+M laugh)
Slappy : (spoken) I don't get it. What's the joke?
D+Sk+P+HN+M: Uhhh...
Yakko : Uhhh...

Dot : I'm a nut who's known as Macadamia
But you can call me by my other nameia
Dot overdub: Louisa
Francesca
Banana-Fanna
Bo Besca.
Dot : Or just plain Dot, the name I flirt to
But if you call me Dottie, I'll have to hurt you.

YW+D : Mac, Mac Mac, Mac, Mac, Macadamia
Mac, Mac Mac, Mac, Mac, Macadamia
Mac, Mac Mac, Mac, Mac, Macadamia
Oy, Macadamia!
Mac, Mac Mac, Mac, Mac, Macadamia
Mac, Mac Mac, Mac, Mac, Macadamia
Mac, Mac Mac, Mac, Mac, Macadamia
Oy, Macadamia
Nuts!