The Japanese-language version of the Hamtaro (Tottoko Hamutaro) theme song is one of the most disturbing pieces of music that you could possibly hear. It's "sung" (mostly shouted) by young children, lasts about 90 seconds in duration, and is kawaii enough to make even the most stalwart anime fan cringe in horror.

The Hamtaro theme ("Hamutaro no Uta") appears in Taiko no Tatsujin 3 as a two-star song on standard mode and a three-star song on difficult mode.

The lyrics:

Tottoko hashiru yo hamutaro 
sumikko hashiru yo hamutaro 
daisuki na no wa himawari no tane 
yappari hashiru yo hamutaro 

Tottoko mawaru yo hamutaro 
kassha wo mawaru yo hamutaro 
daisuki na no wa himawari no tane 
mawaru to ureshii hamutaro 

Tottoko nemuru yo hamutaro 
dokodemo nemuru yo hamutaro 
daisuki na no wa himawari no tane 
yappari nemuru yo hamutaro

The gist of this song: Hamtaro loves to run, Hamtaro loves to visit many places, and Hamtaro loves to sleep. The third line describes the sunflower seeds (himawari no tane) often consumed by the hamsters on the show. I won't bother with a full literal translation.

The English-language version is much less harsh and accents the other characters besides Ham-chan.

Kushi-Kushi Tiki-Tiki woo! 
Hamtaro! 
When we work together it's much better! 
My best friend! 
We like sunflower seeds khrrmp khrrmp khrrmp! 
My Ham Hams! 
If she heads for trouble, we won't let her! 
Hamtaro! 
Little Hamsters, Big Adventures! 
Laura's gone to school, let's go to our Ham Ham Clubhouse! 
We can fix their troubles just be quiet as a mouse 
Watch out for those cats you know they're smarter than you think 
But if we work together we can make their plans sink! Woo! 
Hamtaro! 
Snoozer, Howdy, Penelope, Panda, 
My best friends! 
Oxnard, Bijou, Cappy, Maxwell 
My Ham Hams! 
Dexter, Boss, Pashmina, Jingle 
Hamtaro! 
Little Hamsters, Big Adventures! 
'Scuse me while I work out, gotta run in my wheel, weee! 
Hamtaro! 
Hamtaro's here to help you! 
Hamtaro! 
Hamtaro's team is for you! 
Hamtaro!

Lyrics courtesy http://www.avalon.net/~spoon/HLyrics.html