Are zombies kufr to believe in and is blasphemy if it's both then answer by say both if it's one of them say which one.
Firstly:
The term “zombie”
A zombie is a reanimated corpse that is made to move by means of witchcraft. The word is usually used to describe someone who has been put to sleep and has lost consciousness. From the end of the nineteenth century, the character of the zombie became noticeably popular, especially in North America and in European folklore. In the modern era, the word zombie is used to refer to the living dead in horror movies.
Secondly:
The idea of zombies is in harmony with denial of the resurrection and belief in the transmigration of souls.
According to Islamic creed, there is no such thing as zombies or the living dead who come back to life and eat others, or do not eat. Everyone who dies will remain dead until Allah resurrects him on the Day of Resurrection, and there is no exception to that except in very few cases, where Allah brought people back to life as a miracle for a Prophet of His, as He did for ‘Isa (peace be upon him).
As for the rest of the dead, they will remain in al-barzakh, enjoying bliss or suffering torment, until Israfil gives the second trumpet blast, whereupon they will come back to life and emerge from their graves, as Allah, may He be exalted, says (interpretation of the meaning):
{ And the Horn [Trumpet]. Will be blown; and at once from the graves to their Lord they will hasten} [Ya-Sin 36:51];
that is, they will emerge from their graves.
And Allah has told us that at the time of death, the disbelievers ask to go back to this world so that they might do righteous deeds, and He, may He be glorified, has stated that that will not happen, and that He has spoken and ruled that they will never go back, as He says (interpretation of the meaning):
{[For such is the state of the disbelievers], until, when death comes to one of them, he says, “My Lord, send me back,
That I might do righteousness in that which I left behind.” No! It is only a word he is saying; and behind them is a barrier until the Day they are resurrected} [Al-Mu’minun 23:99-100].
At-Tirmidhi (3010) and Ibn Majah (2800) narrated that Jabir ibn ‘Abdillah said: The Messenger of Allah (blessings and peace of Allah be upon him) met me and said to me: “O Jabir, why do I see you looking downcast?” I said: O Messenger of Allah, my father has been martyred, and he left behind dependents and debt. He said: “Shall I not give you the glad tidings of how Allah received your father? I said: Of course, O Messenger of Allah. He said: “Allah has never spoken to anyone except from behind a screen, but He brought your father back to life and spoke to him directly, and said, ‘O My slave, wish and I shall grant it to you.’ He said, ‘O my Lord, bring me back to life so that I may be killed for Your sake a second time.’ The Lord, may He be glorified and exalted, said, ‘I have already decreed that they will not return (to the world after death).’”
Belief in the existence of the living dead who exist at present or will exist in the future constitutes disbelief that is contrary to what is well established according to Islamic teachings, which is that the one who dies will not return; rather he will remain in al-barzakh until the Day of Resurrection.
The idea of zombies is in harmony with denial of the resurrection and belief in the transmigration of souls. Those who believe in this idea base it on the view that there will be no resurrection in the hereafter; rather a person will die and return repeatedly, without end, or he will die and his soul will move to another body. Denial of the resurrection constitutes disbelief (kufr).
Conclusion:
The idea that the dead can return to this world constitutes disbelief (kufr) and is a rejection of the religious texts. If, in addition to that, there is denial of the resurrection and the reckoning, then this is misguidance upon misguidance.
And Allah knows best.