Mosasaurus (meaning "lizard of the Meuse River") is a genus of mosasaur, carnivorous, aquatic lizards, somewhat resembling flippered crocodiles, with elongated heavy jaws. The name means "Meuse lizard", as the first specimen was found near the Meuse River (Latin Mosa + Greek sauros (lizard)). Since they are aquatic animals, their eggs need to be placed in water.
Mosasaurus in this mod resembles the real-life Mosasaurus. It has a dark green body, a beige underbelly, a crocodile-like head, a beige tail-fin and red eyes. The egg must be placed in the water in order for it to hatch. It is one of two fully aquatic reptiles along with Liopleurodon. When it is fully grown (20 Minecraft days), it will be 14 blocks in length. It can be very dangerous at times of being attacked or not being attacked. It can take 24 hits of a baby Mosasaurus to kill you with full armor.
To get the blue subspecies it must be hatched in an ocean, extreme hills, or any other biome except for plains, forest, and jungle. To get a green mosasaur it could be hatched in other biomes as a rare surprise and in forest, plains, and jungle biomes.
Mosasaurus breed every 5 minutes. The breeding probability is handled by how many individuals nearby.