or put skulk shriekers under their house. it won't spawn wardens but they will be scared. or get a dragons head, put it on a note block and ring it under their house or tame a bunch of wolves, give them armor in the new update, and hit your friend
Pranking in mc

Or.. Just let ur friend be afk and craft a German Banner of WW2 from a loom and throw it at ur friend(name it ur death) and when they come back, Kill them with a netherite sword or an enchanted bow with Flame, Punch and power
not cool. they killed like 10 million inoccent people

replace thier chests with trapped chests and put hoppers underneath.
this will cause it so that only when it is closed the hopper will work

Also go to your friend’s base and put campfires underneath the floor and underneath the ground outside to make it look on fire

put 10 johnny vindicators in someones house. flood their house with water *NOT FACING THE DOOR OR THE VINDICATORS WILL ESCAPE* make sure the water is in different directions so that they wont all be clamped up in one area. This is forced eviction at it's finest. OR box their nether portal, when they go to the nether, the vindicators are all boxed inside and the guy killed loses all their loot

Make a sign and write:herobrine is here is wants to take back what was his. Do it in ur friend’s house.then the next time your friend your friend go out of the house write:this was my land.destroy your house or i’ll do it.if they don’t use TnT to explode his house

Make a room near your friend’s house and put a regular chest in it. Then put diamonds in it. Take a comparator output from the chest and using redstone and stuff, drop your friend into lava or something.
hide a noise machine (example, a bunch of nether portals, or a dispenser that repeatedly shoots arrows at a bell) in/near their base
set a bunch of invis "Johnny" vindicators in their house and farm. put multiple. maybe also add invis skeletons and zombies or netherite zombies