Shaykh Muḥammad ibn Ṣāliḥ al-ʿUthaymīn:

I warn my Muslim brothers against what some of the idiots have made from April Fools day and I think that it (April 1^st) is near, this is a lie that is made from the Jews, Christians, Majūs and the people of disbelief. Then along with it being a lie and the lie is prohibited in the Sharīʿah, it includes the imitation of the non-Muslims and the imitation of the non-Muslim is also prohibited. The Prophet ﷺ said: “Whoever imitates a people is one of them.” Shaykh al-Islam ibn Taymīyyah mentioned that its chain of narration is acceptable.

So at the very least it is prohibited and with what is apparent about it is that is necessitates disbelief for the imitator and it includes along with these two prohibitions a humiliation for the Muslim in front of his enemy, because it is well known from the natural disposition of mankind that the one who is being followed has disdain for the one following him, he feels he is superior to the one following him, due to that his blind follower is weakened such to that he must follow him and in this is humiliation to the believer since he becomes submissive to the disbeliever.

The fourth prohibition is that in most cases this evil lie involves consumption of wealth with falsehood or it involves deceitful surprise for the Muslim, for perhaps he will lie and speak to his family and say “So and so says there is a group of people coming home with us today..” So (the people of the house) will cook a large dinner and whatever resembles that or it may be that he will inform them of something that will shock them. He may say “your caretaker has been run over by a car…” and whatever resembles that from the affairs that are not permissible from the outset let alone in such a condition.