Note: Make sure to name your alligator gar with a nametag. They will despawn otherwise.
The alligator gar is a small, passive, aquatic, Mesozoic creature that was added in Build 7.3, the Dinosaur Renaissance update. It is a living fossil fish that spawns naturally in the world but can also be created by the player, similar to the nautilus, sturgeon, and coelacanth, all of which also spawn naturally. It is around 1 block tall and 3 blocks long and drops raw fish when killed. Groups of alligator gar spawn in swamps, replacing the old fictional Swamp coelacanth subspecies. Right-clicking a alligator gar puts it into your inventory as an item, which can be cooked.
Alligator Gar is an aquatic mob that can spawn naturally in the world. They spawn in water in swamp biomes. Since they are passive mobs and do not defend themselves, they are vulnerable to the marine predators mosasaurus, sarcosuchus, spinosaurus, and liopleurodon. They can only live underwater; when placed on land, they flop around, dying of suffocation at a rate of one heart per second. Right-clicking catches them, and then you can release them into the water or cook them to eat.
Like other living fossil mobs, they cannot be tamed, ordered, fed, bred, or aged, and do not have genders or moods.