Basically the product of an Argy (high weight and looks like one, minus the corrupted face), Daeodon (healing), and Griffin (dive attack). I would pick these over almost any Extinction creature, besides Velonasaur. And yes, this includes the Managarmr.
They can thermally detect any living thing around you giving a strong pvp advantage. Like a night vision with wings. Plus they can put you and your allies in stasis and heal you whilst being an ice cube. Decent airborne mount -
If you are taming something and have an owl, you can use its freezing ability to heal it. It does not affect torpor or taming effectiveness. This way if the dino gets hit, you can heal it fully, and then let it wake up so you can try again without the risk of killing it.
These bad boys are super useful for taming, they can help you grow plants, slow down things you’re shooting with tranq with their dive, they can heal low hp wild animals so you don’t kill them and etc. Did I say they can detect wild creatures in the dark too? Best airborne mount before wyvern and rock drake.