Ibn Abbas (may Allah be pleased with them both) says that the Prophet (peace and blessings be upon him) said concerning the one who commits bestiality with a beast: "Kill both the doer and the one to which it is done."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 17034
Sayyiduna Ibn Abbas (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) said: "Whomever you see committing bestiality with an animal, kill them both, the animal too." It was asked: What is the animal's fault? He said: I did not hear anything about this from the Prophet (peace and blessings be upon him), but my opinion is that benefiting from that animal, or eating its meat, is now disliked.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 17035
Amr (bin Abi Amr) narrates with his chain that the Prophet (peace and blessings be upon him) said: "Accursed is the one who commits bestiality with an animal; and kill both the doer and the one to which it is done, so that it is not said: This is the one with which such and such was done."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 17036
Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) says that the Prophet (peace and blessings be upon him) said: "Whoever commits adultery with his mahram woman or with an animal, kill him, and kill the animal too."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 17037
Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) was asked: What if someone commits bestiality with an animal? He said: There is no hadd punishment upon him.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 17038
Abu Dawud (may Allah have mercy on him) said: The hadith of Asim weakens the hadith of Amr bin Abi Amr.
The Shaykh (may Allah have mercy on him) said: We have narrated it from Ikrimah through several routes, and I do not consider Amr bin Abi Amr inferior to Asim bin Bahdalah in memorisation; how could that be, when a group has corroborated him in his narration? And Ikrimah, in the view of most of the imams, is among the thiqat (trustworthy) and firm narrators. And Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 17039
Sayyiduna al-Hasan bin Ali (may Allah be pleased with them both) was asked: If someone commits bestiality with an animal, what is the ruling? He said: If he is married, he will be stoned.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 17041