rather than shooting them with a nerf gun, id personally recommend shooting them with the tree.
Prank Ideas!

Sneaking into a room and scaring your friend.

dont just scare them, traumatize them, a fake knife, some fake blood, and an extra friend, stage a whole murder scene as you had just tried to scare them, but someone else was in the room, put up a fight, futile as they watch their best friend get stabbed before their very eyes...

Replacing Cheetos with Extra Spicy Hot Cheetos.

while normally this would work, it happens that your friend loves extra spicy hot cheetos, so what do you do? simple, you buy 3 ghost peppers, 2 carolina reapers, and one pepper x, take out the seeds, blend them together, and dip the cheetos in this new mix, giving it to your friend to enjoy their spicy demise.

as for the next prank... hidding your friends wallet in their car, in the glove box where they never look

Hide your friend's wallet in their car in the glove box where they never look, and put their ID and car registration under the back seats.

don't just reveal it... quiz them, first question, "what was the 3rd thing you searched on march 3rd 2023," incorrect, now, that will be sent to your mother whom is on her deathbead, prepairing to write her will, "what was the 7th thing you searched on November 21st 2024?," incorrect? oops, accidentaly sent your whole november search history to your girlfriend, good luck keeping that relationship active...

i was saying blend the seeds, but that probably would make it easier to blend

Reveal their search history, quiz them, send it to their girlfriend and mother, make a live broadcast on the news about it.

mmm... kinky, (i should not be saying this)
Tapping someone on their shoulder and then running away.