These things can stay hooked to any surface even when unmounted. If you live in a cave or wanna set an ambush leave them hooked to the cave entrance ceiling on agressive and taunt your enemies to follow you into the cave.
These can be used as a deadly bioweapon against enemy tribes:every bite of a megalania has a chance of inflicting highly contagious health draining rabies, so just one bite from a megalania can kill many more players and the rider of the megalania is immune, that combined with their brilliant wall climbing ability means that they can sneak into an enemy base and spread a deadly plague which can only be treated with a lesser antidote which is incredibly difficult to get seeing as the best way to get it also inflicts a deadly disease only curable by it
You can shoot from its back 360° unlike other creatures that only have a 180° range (half circle) to Climb you must right click. Its very helpful for taming things because you can shoot from any angle and stick to any surface