Contest design 1: Lacus Deer

My first entry for Vixenkiba 's contest to design creatures for their world.

This is the Lacus Deer, or Lake Deer. They're called that even though they have no relation to deer at all. They are intelligent and playful and can be tamed. Once tamed, they can be ridden in the water. People use their 'antennae' to steer them. Lake Deer are fast and have strong front flippers that propel them through the water. They can also walk on land but arent as quick.
They mainly come in dark blue or steel colors, with brighter colors on their fins. Sometimes they can be muddier colors too.
They are usually around 8 feet long and weigh roughly 150-300 pounds. They feed on fish and mussels in the lakes they inhabit. The inside of their mouths are lined with small sharp teeth that latch on to fish, which are then swallowed in one gulp.