Everyone seems to limit this to just being a "scout". If you get a high level (170+) the terror bird can easily be one of the most deadly mounts out there. It's speed is unmatched and its ability to glide from any height, if it has the stamina that is, makes it amazing. If you pump HP, speed, stamina, and later on movement speed, you will have an absolute killer. (WARNING: Even high level terror birds will have low weight, only bring your essentials to maximize on speed!)
Perfect mount to explore on the ground. Everyone uses a ptera to get around the map, but on the ground it's a whole different experience. Also this mount is my go to for cave exploring. 300+damage and 180+movement speed is a must.
It is pretty much a raptor that can glide through the air. The thing is that it isn't an early tame, which is why it is less useful. Since it's a harder tame than a raptor, you can better tame a carno at that point.
These make decent scouting mounts. They're relatively quick & their ability to glide by holding the jump button can get you out of some sticky situations that wouldn't be possible on a raptor (jumping from a cliff to escape predators). I suggest leveling in Health, Stamina, & Melee (Movement Speed as needed).
The Terror Bird is a great scout. It's high speed and ability to glide makes it useful for escaping other predators. However, it does have pretty low weight, and sometimes low health, so I would level up its weight capacity and it's health. ( But that's for the Terror Birds I found, as they had low weight and slightly low health. If you find ones that are better, mine might be weak or a lower level, so do as you want! I hope this info was a bit helpful :D )
Terror birds are by far one of the most efficient, and fun land mounts one can own. Not only do they have a great run speed, but their glide ability can save you from everyone's greatest enemy, gravity. That all said, the Terror bird is not a mount that can trade blows. It is best utilized for ambushes and covering rough terrain. UPGRADE: HEALTH, SPEED, STAMINA.
The Terror bird is hands down the best tame to use to clear the lava caves. Their gliding ability allows them to easily cross gaps with little worry of falling in. Good base stats for a cave runner terror bird is 2000 Hp and 300 melee. After imprinting pump Hp between 3000-5000 and pump the rest into melee.
Now while taming these takes alot of resources and time finding a high level 100+ tbird will help you. On top of a fast and stable mount it can gather meat fast and have good stamina balance. I honestly think this should be higher on meat gathering.