Here's one more:

ORIGINAL TEXT:
All right stop
Collaborate and listen
Ice is back with my brand new invention
Something grabs ahold of me tightly
Then I flow like a harpoon daily and nightly
Will it ever stop?
Yo-- I don't know
Turn off the lights and I'll glow
To the extreme I rock a mic like a vandal
Light up a stage and wax a chump like a candle

SPANISH TEXT:
Toda la parada derecha colabora y escucha hielo está detrás con mi invención brandnew que algo ase el ahold de mí entonces fluyo firmemente como un arpón diariamente y cada noche voluntad él siempre parada? Yo -- no sé doy vuelta apagado a las luces y brillaré intensamente a la roca del extremo I que un mic como un vándalo enciende para arriba una etapa y encero un chump como una vela

ENGLISH AGAIN:
All the right shutdown collaborates and listens to ice is behind with my invention brandnew that something roasts ahold of me then I flow firmly like a harpoon daily and every night always stopped will he? I -- I do not know I give return extinguished to the lights and will shine intensely to the rock of the end I that a mic as a vandal above ignites for a stage and encero chump as a candle

I particularly like "extinguished to the lights and will shine intensely". The main problem is that in the initial translation, any slang is translated to an exact equivalent in the other language (ignoring it as slang). So, when you translate back, the whole meaning of the slang word is lost.