Lyrics:
Battle Against [bad word] Hero

[Undyne]
I’m a hero and I swear I will take you down!
All have failed, but I will spear you to the ground!
Slaying monsters that are sometimes twice your size…
Heartless body without a real soul inside!
I won’t let you get away with what you’ve done…
You have dusted he who’s brighter than the sun!

[Chara]
Funny, you have got to be kidding me, Undyne…
What will you do when it [bad word] your time?
I [bad word] that pathetic whelp’s skull into dust…
He much too easily endows all his [bad word] 
Despite your strength, it won’t take long for you to fall
Crashing down, though right now you are standing tall!
I’m really getting a kick out of this battle
Soon I’ll have your head and a melted puddle

[Undyne]
I will not fall…
I must save
All of the kingdom…
It’s my job!
I’m standing tall…
Just for them…
With nothing to lose…
He’s gone…!

[Chara]
I can’t recall…
The last time...
That was this much fun!
What [bad word] !
Slow to a crawl…
Speed it up!
You can do better!
Promise~

[Undyne]
Every time I raise my spear, I can’t help but see his smile…
Telling me that it’s alright; I have to protect all the rest!
You won’t break me down; you’ve got nothing but a narrow aisle…
Seemingly your LOVE is high, so I’ll put you to the test!

[Chara]
I am starting to get bored, better hope you keep me amused…
As soon as it isn’t fun, I’ll just be more determined!
I really missed the adrenaline from being so [bad word] 
On the verge of death; let’s finish this!

[Frisk]
You can’t hear me scream your name, but I swear I’m calling out…
I never wanted to press fight, but I’m not in control!
Remember, we were friends before? So just end my life, Undyne…!
I can reset all of this terror…