Remove/Change Loud and Repetitive Croak Sound Tyrannosaurus makes when Sitting
The particular soundbite Rex makes when transitioning into a sit is extremely overbearing. Not only is it repetitive, as eating produces this sound along with most of its emotes(yawning, stretching,grunting, even digging), it is a signifier for everyone around to let them know you are there.
This would make sense if playing as Tyrannosaurus was stealthy and players generally would have a hard time tracking you, or if Rex's speed made it more of a threat. But Rex is extremely slow, and his footfall is enormous. Things can already hear you from simply walking around.
You are already a massive target everywhere you go, and when you sit, you simply make yourself even more obvious, which isn't conducive to fun gameplay when all you want to do is travel without bringing much attention to yourself.
Another sound that isn't as repetitive would be a good option too, but sadly for now, the current Sitting Down noise Rex makes can get on your nerves extremely quickly.