Use '/tag @p add give' to obtain the items.
Items:
1: Bendy Piston/Sticky Piston.
Placement acts like a normal piston.
Place more on the white particals to extend it.
Has a max of 12 blocks.
Does NOT allow slime block behaviors.
Can push and (sticky) pull ANY minecraft block, which can be confusing.
Does NOT require direct redstone contact, can NOT be used with target blocks (for connectivity).
Makes the pink stained glass block/pane invisible as its used as the base for the piston.
2: Custom TNT.
Take a look at this video for instructions (6:25 - 7:54).
3: Blue Shell.
When spawned, it will follow and kill the nearest player (excluding the player who spawned it, unless on singleplayer) on impact, just like in Mario Cart.
4: Sharkzooka.
Retextured crossbow (DO NOT RELOAD MANUALY, it does it on its own).
When fired, if at ground, all mobs (hostile or no, excluding players and mobs 5+ blocks in the air) within an about 12 block radius will get chomped to death.
5: Mars Rover.
Exactly what it sounds like.
Right click on the seat to enter (Retextured horse, DO NOT KILL IT, this will soft lock it).
Right click on the drill button to activate drill.
The drill, when activated, will, well, be a drill, breaking blocks in front of the rover. You WILL get the items as if you had mined them by hand.
Right click on the claw button and the claw will reach out in front of the rover and put it in the back seat, simply crouch to get out of the seat.
6: Traffic light.
Exactly what it sounds like. No more is needed to be said, other than remove the bottom barrier to remove.
7: Beyblade.
Bounces off of other Beyblades and blocks when spawned it.
Slap it to remove it.
8: Demonetizer
Lets just say, Youtubers hate him.
Illegal Blocks by CommandGeek (1.17+)
From https://www.commandgeek.com/projects/illegal-blocks ,
"Ever wanted to place blocks in ways they normally can't? With my datapack you can make hilarious and cursed builds with these weird blocks. While holding a sticky piston in your off hand and the desired block in your main hand, sneak to spawn in a movable block. Right clicking the block with a carrot on a stick will push it by 1 pixel in the direction you are looking. You can push regular blocks into the ground to make slabs, push blocks into each other to make weird optical illusions, or simply move them around in ways that look very, very cursed. Throw a TNT on any cursed block to remove it from your world. It's completely vanilla Minecraft so you can prank your friends with it!"
Weird Sword by CommandGeek (1.18+)
From https://www.commandgeek.com/projects/weird-sword ,
"Instead of crafting 2 diamond swords into another normal swords, you can craft it into a "Weird Diamond Sword" instead. This is a bent sword which can do much more damage with every use. Adding more swords to the crafting recipe makes the pickaxe more and more cursed, resulting in the " Weirder Sword", "Weirderer Sword", "Weirdererest Sword", "Very Weirdererest Sword", "Veryer Weirdererest Sword", and finally with a sword simply named "stop". This item is extremely cursed, and there is only one way to figure out what will happen if you use it..."
Use '/function weird_sword:dummy/spawn' to spawn A LOT of cows.