The Coconut Shooter resembles a hollowed-out log with a with twig sticking out of it (this is possibly the weapon's crosshair).
In Donkey Kong's case, the earliest opportunity to buy it is in the area Jungle Japes, the first area of Donkey Kong 64. It is impossible to beat the level without the Coconut Shooter, as Coconut Switches are the only ways to open the gates to the level's depths (and free Diddy Kong from his cage).
Like all of the Kongs' weapons, Donkey Kong draws the Coconut Shooter by holding Z and pressing the left C button. He can also use the top C button to enter the first person view for more ease of aiming, and after obtaining the final upgrade, can press the bottom C button to zoom in on his target. Pressing the B button fires the ammo.
Upon turning the game on, the weapon's ammo will be at half of its maximum capacity of standard ammunition. If the ammo runs out, the Kong must either visit Funky's Store to max it out, or pick up ammo crates, which are abundant in the game's various areas.
The Coconut Shooter gives Donkey Kong gains the ability to shoot Banana Balloons, snipe enemies from afar, and most importantly, trigger Coconut Switches.
- Interestingly, beta-screenshots of Donkey Kong 64 showed that the Coconut Shooter was originally going to be a weapon similar to a double-barrel shotgun.