As'salamu Alaikum akhi Uzair,
Notice how your statement and the quote contradict each others. Your statement asks for a Noble Verse or Hadith that forbids bestiality, while the quote you quoted questions whether the punishment for this crime should be the death penalty. So right from the start, it is at the very least considered a sin.
Anyway, I have thoroughly demonstrated from the Glorious Quran and the Hadiths that bestiality is forbidden in Islam. Please visit:
http://www.answering-christianity.com/christian_prince_rebuttals.htm.
Please feel free to ask more questions.
Take care,
Osama Abdallah