I find that the best way to encounter these beings is by not having the equipment or dinosaurs to knock it. The level is determined by distance from your base/supplies (easier to get supplies=lower level).
So let me tell you a little story so I had a quest telling me to tame a quetzal
And I was a good level for the saddle but boy was I not thinking I had argent with me and my grapple and was ready but the quetzal I was taming got away and then my argent was stuck in the air he could follow because I had him not to follow me and then I wanted to come back for him/or her I don’t remember but when I came back........it was gone
They aren’t always near obelisks. I have been searching for one for days now, have circled the island many times and even done a server reset and have yet to see one near an obelisk. The 2 I did find were near the redwoods and died upon KO due to a troodon pack
From my experience there are sometimes 2 on the Ragnarok map. They can be found around the beaver dams at redwoods and below the castle. As well as the snowy areas near those locations They also find their way into the scar rarely. If you are having trouble finding one they might be stuck on obstacles especially in the snow above the scar and trees and rocks in the redwoods.