The most efficient creature is hands down the Carno. Easy to tame and gives a third of the XP a Wyvern of similar level would give. Just be sure to weaken them beforehand because the night isn't long enough to watch a Troodon eat 3 lvl 200+ Carnos all the way through their 2,4k-4k HP.
Oh and start the tame as soon as the night falls, not sooner, not later.
At lvl 72 with flak armor on, a lvl 5 Troodon knocked me out with one attack at night. Last thing I saw was those glowing eyes before passing out. My Guess is that they attack vital organs. Luckily my Doedicarus was up for a game of baseball and launched that little devil out into the stands.
Went to go grab a drop during the night on my dragon. I was wearing full Master Craft Flak Gear and two bites from these little sneaky bitches and I passed out. Luckily my dragon was on nuetral. Unluckily that it's fire breath roasted me too. Lesson learned:
Burn everything on fire before you get off your mount...
Step 1: make a taming pen.
Step 2: put a lvl 80+ baby wyvern into the pen. Knock it out if you want to and lower its health down to almost 0.
Step 3: Drop troodon inside while its eyes are glowing.
Step 4: Enjoy your tamed troodon