I remember this one

REALLY looses its purpose when you actually know most of the Japanese Pokemon names tho...

EDIT: here are the lyrics copypasted from bulbapedia...

Hello Kids!

Have you also caught a lot of Pokémon?

I challenge you who got a hundred and fifty-one Pokémon,

as well as you who haven't yet,

(Can you say Pokémon?) I challenge you!

How's your mouth rolling today!

Pikachu / Kairyu / Yadoran / Pigeon

Koduck / Koratta / Zubat / Gallop

Thunders / Menokurage

Pawou / Karakara / Tamatama / Garagara

Fushigidane!

Arbo / Eivui / Utsudon / Eleboo

Kabigon / Kabuto / Sidon / Jugon

Porygon / Digda / Dodrio / Gengar

Dogars / Rougela / Nyarth / Showers

Kusaihana!

La, la, la, can you say them?

Can you say them?

la, la, la, can you say them?

The names of Pokémon!

Cocoon / Ghost / Iwark / Hitokage

Lucky / Ratta / Onidrill / Coil / Rarecoil

Pukurin / Zenigame / Nyorozo / Tosakinto

Fire / Booster / Foodin / Boober

Strike!

Caterpie / Pixy / Seadra / Raichu

Hitodeman / Crab / Nidoqueen / Sandpan

Azumaou / Transel

Dodo / Tattu / Gardie / Mankey

Dokukurage!

La, la, la, can you say them?

Can you say them?

La, la, la, can you say them?

The names of Pokémon!

Now let's try changing styles!

One, Two, Three, ah-here we go!

(Yeah) / Onisuzume / Sand / Parasect

Sleepe / Beedle / Kailios / Pigeot

Koi-king!

Sihorn / Matadogas / Fushigisou / Kamex

Shellder / Thunder / Lizardo / Nassy

Betbeton!

Poppo / Utsubot / Purin / Casey / Betbeter

Garura / Gyarados / Golonya / Pippi

I-si-tsu-bu-te!

Golduck / Omanyte / Golbat / Arbok

Nidoran (female!) / Nidoran (male!)

Na-zo-no-ku-sa!

It sure feels good

La, la, la, can you say them?

Can you say them?

La, la, la, can you say them?

The names of Pokémon!

All right.

Next, how about singing them while crying?

Nyorobon / Kamonegi / Laplace / Ruffresia

Kabutops / Nidorina / Barrierd / Marumine

Fushigibana / Paras / Lizardon

Kongpang / Yadon / Metamon / Ghos

Biriridama!

All right, kids.

It's time to take a break, here.

Wonderful creatures

Animal picture books don't have 'em

Pocket Monsters Pokémon for short

It's really something if you're able to say them till here

But, the hard part starts from here

Hookay! It's the last part Let's give it a shot

One, Two, Three, ah-here we go!

Yungerer / Kingler / Sawamular / Ebiwalar

Kairiky / Sleeper / Goriky / Starmie

Madatsubomi / Ptera / Nidorino / Persian

Hakuryu / Mewtwo / Kyukon / Spear

Beroringa!

Butterfree / Dugtrio / Nidoking / Omastar

Parshen / Nyoromo / Golone / Rokon / Kentauros

Ponyta / Monjara / Miniryu / Wanriky

Morphon / Kameil / Windie / Freezer

O-ko-ri-za-ru!

La, la, la, were you able to say them?

Were you able to say them?

La, la, la, were you able to say them?

The names of Pokémon!

La, la, la, were you able to say them?

Were you able to say them?

La, la, la, were you able to say them?

The names of Pokémon!

Okee-Dokee!

Now that's the way to say it.

Huh? Wait a second!

Aren't we forgetting one more?