Plesiosaurus

The Plesiosaur (meaning "near to" and Sauria) is a marine reptile based on a real life plesiosaur (the exact species is unknown likely a disproportioned elasmosaurus) It is a piscivore, and it can be tamed.

Appearance
The Plesiosaur is a long-necked marine reptile, with an orange body, a slightly darker back, a white underbelly, a tail, and four flippers. Its neck is actually short for a Plesiosaur, as some Plesiosaurs such as Elasmosaurus had even longer necks.

Behavior
The Plesiosaur is a passive mob. It is a semi-aquatic creature—it can live on land as well as in the water. When Plesiosaur is at the bottom of a body of water, it will catch fish for itself. It will also attack dodos and chickens when hungry. When it is tamed, and is old enough (6 MC days or older), you can ride it. You have to right-click it and then you need a whip in order to control it. Plesiosaur can be ordered with a magic conch or an empty shell to stay, free move, or follow. Putting the conch in the crafting table will change its command. All commands will order all Plesiosaurs in a 30 block radius to do that said command.

Edit note 1.6.4: The Plesiosaur seems only to be moving freely when ordered "free move" if he is in water. On land he just sits there not moving.(Cannot move on land)

Rideable
Like some of the other dinosaurs, Plesiosaurus can be ridden using a whip. As of now, the riding handles more like as if you were driving a boat. Pressing W will send you in the direction that the Plesiosaurus is facing and vice versa for S, while A and D will just pivot the dino on its axis.You can start to ride it at about six MC days (two real life hours) after hatching.

Trivia

 * The plesiosaur and the mammoth are the only mobs with a unknown genus.
 * The plesiosaur is the only tameable swimming creature.