Just find one in the wild with a baby and kill it then imprint the baby

there everywhere around green obelisk

To tame, you need to make alot of Hemoglobin. This requires killing alot of wild Ceratos and then using 10 of their Venom spines and some blood packs to craft one.

You then need to find a wild cerato. Use a tanky dino with a really good saddle that can take a beating. Let the Cerato start to attack you. Then feed your dino a hemoglobin. Do not attack at all, you have to let it attack your dino. Stay on your dino and keep the Hemoglobin effect on your dino. Special effects will appear and the Cerato will start show "drunk" percentage numbers pop-up. Once it hits 100% you then have to have superior kibble in last hotbar slot and follow it around and passive feed it.

They dont like being too trapped (just won't tame). If you have room, place a 2x2 of behemoth gates to give them room to move around when attacking you.

Bring plenty of Hemoglobin! I play on a 5x tame server. We are 10x tame right now for the Holidays. Even on 10x they are a super slow tame at high levels! Patience is key!

-AJ

If you're early game and want a cerato as early as possible but can't or won't find a baby or you can't kill the cerato just lead it to something that It will fight (I would personally go for a theri since they spawn in the same rough areas) and then collect the venom spines from its bag ;)

If you want to tame yourself one of these my personal favourite creature to tank hits is a 100% imprint Archelon. high HP and Resistances make it an absolute wall against all hits.

Easy to get drunk if you have a Rhy Bug, pick it up, active the hemoglobin cocktail while you transport to a safe location, drop once drunk and feed in safety.

They eat meat after tame.

Feed the hemogoblin to a brachiosaurs to tank the damage ( Brachiosaurus is also from ark additions)

Scoop up your wild Cerato with your Rhynio.

Feed Rhynio the Hemoglobin cocktail.

Cerato will attack the Rhynio while you carry it to a safe spot wait until fully drunk then do the passive tame in the safe location.