All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The Hadeeth is Saheeh. The Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said that on the Day of Resurrection death, will be presented in the form of a big sheep, then it will be slaughtered in front of those who will enter Paradise and those who will enter Hell so that they know that there is no more death, only eternity in Paradise or Hell. Al-Bukhari, Muslim and others narrated this Hadeeth on the authority of Abu Sa‘eed Al-Khudri .
Some people might think that 'death' here refers to 'the angel of death' - this is wrong. 'Death' here refers to death itself. Allaah will make death like an actual sheep. Such things frequently occur on The Day of Resurrection, for example Allaah will make the actions of a person perceivable and tangible, and able to defend him, or testify against him etc.