It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that a person asked the Prophet (peace and blessings be upon him) whether a Muhrim (one in the state of Ihram) can kill a snake? The Prophet (peace and blessings be upon him) said: There is no harm.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 11273
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضعيف لضعف شريك النخعي، ويزيد بن أبى زياد