You can breed them while they are mounted on the wall. I found it's the best way to breed them because they don't move around. But be carefully their egg goes to the other side of the wall so make sure you have access to both sides.
I love these guys. Don't think of them as standard battle mounts. I use mine to have a really fun time tracking and hunting down creatures in the Ragnarok canyon. Because you can shoot from it's saddle, you can wait to ambush potentially dangerous creatures from the walls and bridges. By far my favorite hunting mount.
Once tamed they are actually okay at swimming and excellent guard animals for if you're base gets raided just put them on the ceiling and when someone breaks in it drops on them and gives them rabies which will generally kill them quickly
This gravity-defying lizard has a high HP count, over the top stamina and descent weight, but don't count on its melee attacks: To balance the poisonous bite, the damage itself is as low as that of a raptor and the attack speed is is extremely slow. Their speed is also not what you would expect, but they have just the enough amount to rapidly climb walls.
Best used with high damaging portable firearms, such as Pump-Action Shotguns, Assault Rifles and Fabricated Sniper Rifles.