Rhyniognatha (lvl 150-170) [PvE Cross]

The way to acquire Rhyniognatha is probably one of the most complicated ones in the game. You need to kill a male Rhyniognatha to acquire its pheromone, then once you find the rare high-level female Rhyniognatha, you need to lower her health below 10% without killing it. When it's hurt enough, the pheromone is fed to your Giga/Carcha/Brontosaurus and if Ark Gods allow it, the female Rhyniognatha will impregnate your sacrifice. Then every couple of hours it will require a special material/food to keep the chance for good baby stats high.

This comes with a great reward, as it has a lot of abilities:
Walks on water, swims underwater
It can be maneuverable sideways, hangs on vertical surfaces, and has a passenger seat!
Lets you use weapons while mounted
Roars to fear its opponents, just like a Yuty, by pressing C.
Passively turn sap into resin in its inventory
Makes resin-made armor by pressing Control + C
It has several attacks, you can cycle between them by pressing Control + Right Click (requires resin to shoot)
It can grab, carry and move structures like an Exo Mek (will destroy if runs out of resin)
It can carry big creatures like a Rex, Yutyrannys, Spinosaurus as well as smaller ones! (Control + left click)
It has amazingly high weight and flies faster than Argentavis (when not carrying a tame)!
 
The better the host for the pregnancy the higher the level of the female Rhynio, the better the stats. That's why each Rhyniognatha is unique and there can't be another one just like it. They also can not breed and only low levels can be cloned (which is very expensive) guaranteed for it to be an elite tame!
 
The stats are visible in the screenshot, no levels have been spent.