Probably the best platform dino to live on, the megachelon can fit a 5 by 7 of foundations on its shell, and many structures, like chemistry benches, grinders, and even industrial forges can be built on it while staying there when underwater. You don't even need scuba gear when going underwater, staying above one provides oxygen. Not only this, but they actually have surprisingly good melee damage, as well as being one of, if not the best fiber harvester in the game. Different resources will constantly build up in its inventory, including rare mushrooms and flowers. They also automatically irrigate any crops placed of them. Get an imprinted one for extra speed, damage, and resistance, then give it an good armor saddle from the frog escort mission in the bog, and you have an extremely tanky resource gathering portable base, war machine, greenhouse, and water exploration mount!
Fun fact use it in the lunar biome to gather stone, crystal, wood thatch fiber like crazy from lunar bushes, go to the Arctic to get sap from trees, go to ocean to get silk and plant y seeds and big biome for plant x from those narco plants. Volcano needs testing to see what it's good for. Enjoy building stone behe gates in lunar :)
Passively generate rare flowers and mushrooms with seeds in its inventory. Collects fiber like crazy. One of the only that can collect silk and y seeds on genesis efficiently. Mine has 20k hp 400m (145 perfect tame) 120 armour saddle, and has killed a 150 x mosa. It's safe to say these dudes are AMAZING.