Realistic Lapras

I know it looks alot like MetalReaper's Lapras, but its not. MetalReaper's Lapras just looked amazing so I wanted to do my own spin on it.
Lapras: This pleiosaur like pokemon swims the seas of the pokemon world. But do to poaching, their numbers have decreased over time. As they grow up and mature, coral and algae grows on their backs and form the turtle like shell, their ear like plates on both sides of their head is actually part of the skull so their brain is larger and can understand and reply back in english or the language of the trainer or person. No one knows what the horn is for, but there are two ideas, one is: it is used for a hunting tool, like a spear, or the second one is: it is used for mating, the males using them for fights to win the female.