T. rex needs a model TLC(Minor changes for a vast improvement, I promise!)

Your rex is all things considered, good, but I'm gonna be honest with you. Its generic and conservative for a Rex design. A lot of people just don't find it visually appealing

So I have all the changes you'll need to do, and luckily its a short list!

1. The head, the keratinous coverings are TOO conservative. These would of likely been very ornamental, whether or not that means they're extremely colorful or big its up to interpretation, although both is also likely!
For reference look to Saurian, BoB, Beasts of the Mesozoic, and Prehistoric Planet.
All those rexes are fantastically designed while also being up to date in terms of accuracy. I suggest making the Pot Rex stand out too! Go crazy on those keratinous ornaments, it'll give Rex more character, personality, and make it visually appealing while also remaining within reason!

2. The skins, I know, its incredibly subjective. But besides 1 none of the skins accentuate the crest/keratin. Make new ones that do! Make them stand out!