Terra Aecor is a Lapras that Team Rocket experimented with while it was still in the egg. They injected it with a serum made from Torterra DNA and various other things. When it hatched and was still only the size of an average turtwig they transplanted the shell of a Turtwig onto its back. Even though Lapras doesn't evolve, Terra underwent an evolution when a Turtwig usually would. The shell evolved into Grotle and a few physical changes occured to Terra but not many. However when it came time to become a Torterra, the whole of Terra Aecor undertook massive changes fully excepting its shell.
Team Rocket also experimented with a Lapras and Blastoise shell, and while it was an effective experiment, the Lapras didn't gain any new type of major abilities.
Terra Aecor however became part grass type
The name Terra Aecor comes from the Latin words for Earth and Ocean.
This one was made the same as the others already done. On lined paper and with a photo taken of it. I then fixed it on the computer (time consuming- I wish I had a scanner...) and coloured it.
Separately the Unevolved form of Terra Aecor is here [link]
The 1st evolution is here [link]
And the 2nd evolution is here [link]