Hackers do something called, "Boats"

I have a custom character, and when it dies, it should disappear like all other characters. But some people or hackers I believe jump to the water (the world border, basically a kill part), and somehow glitch it. To leave their character there.

Another idea I had was the leftover characters. When they spawn as this custom character, it’s manual. So, I don’t know if there’s this issue where it’s spawning but is left there. I’d see these “boats” much more often if that happened, since this custom character appears a lot in my game.

Anyway, here’s the code that changes their character:

wait()

local charged = game.ServerStorage.Characters["Charged Creeper"]:Clone()
charged.Name = player.Name
player.Character = charged

charged.Parent = workspace

wait()

Note that there’s spawning code under it (they go to a spawnlocation)

You could try deleting the model of your monster when the player dies or enter in contact with the kill brick.

They may be doing a roblox glitch where they hold the close or X hold a button for movement then bring the cursor on screen and let go avoiding the kill part so you could try to make multiple or make it wider.