If you want to kill someone harmless, pick a weapon from 1. If you want to kill a threat, pick one from 5.
Freeze ray, clone gun, boomerang
Boomerang with weapons glued to it, car with a spiky object glued to it, resurrective bomb
1. Place one invisible glue in the middle of the cannon. 2. Stick the skull on. 3. Place the other invisible glue in the middle of the tyre( the empty space). 4. Empty the cannon and place your ammo inside. 5. Stick the cannon on the tyre. 6. Ride the tyre. It rolls around! To fire, interact with the cannon. 7. (optional) Do away with the ammo, get a rope and attach it on the tip of the cannon. Now you have a giant bomb!