Kill the parents using a strong mount like a Thylacoleo, then claim the babies for easy Ossidion.

Solo is hell, Duos is far easier. Use a Zeppelin to hover above, lower partner with grapple, tranq like that and drop them on it. Then they do its tame mini game, rinse and repeat. Zep keeps you both out of the way and can provide respawn if things go sideways. Solo is a good way to stress yourself into a stroke 🤣

You can use a mate with a snow owl to freeze heal it as you reapply torpor keeps it alive.... and your tribe mates count as small creatures i believe... more testing required

Easiest way is with two people. Bring longneck, shocking Trang darts if you have them. Something tank to protect and take hits like a Carcharodontosaurus, a snow owl and a tek suit. Person on carcha takes agro and clears area. Person with longneck tranqs it while using tek jet pack if you have one. As soon as it stuns person who is tranqing jumps on and rides it while charcha rider protects by taking out the larger wild dinos. Person riding Ossidon calls out when he is about to get kicked off and carcha once again takes agro. If needed at this stage person who is on tranqing duty should pull out a snow owl and heal the Ossidon by freezing him. Rinse and repeat

Not a boss, is tameable. Spawns in glacial areas, rare spawn chance. Size is gigantic.

tranq it to half of max torpor.

approach it and ride it.

it will start making a mucus ball and launching icicle spears into the ground aim up hill for icicles.

walk over and meet requirement for icicle spears and small tames (avoid big tames like Yuty, galli, mammoth, rhino) with the ball and u gain taming effectiveness and progress

u have a timer, after it end it will kick u off and u need to start Trang again

Pretty easy tame with 2 people. Tanky dino with a good saddle helps. Giga/carch are tall enough to prevent rider from taking damage. Bring 5 carbo or similar tanky small dino (Stego and trike to large). Kite to a safeish location with a slope. Toss out the carbo a little bit away from the ossidon. Have your tribe mate take aggro with the tank suggest 30k hp with 70 plus Armour saddle. While you Trang. Jump on when its dazzed pick up the ice and carbo in the snowball rinse and repeat if lucky finish in 4 go on 1x.

(Found on Reddit)

Quick Guide to tame Ossidon

tranq it to half of max torpor.

approach it and ride it.

it will start making a mucus ball and launching ice spear into the ground.

walk over the spears with the ball and u gain taming effectiveness and progress.

u have a timer, after it end it will kick u off and u need to start from scratch again

tips don't do it downhill and avoid it getting stuck

To start the taming for the ossidon, you need to get its torpor halfway, then ride it. Collecting icicles and creatures into the ball will progress the taming & filling the quota bars will keep taming effectiveness after dismounted