This is why the leg/shoulder/rump cuts of beef are tough.
The more the muscle is used, the 'harder' it gets.
[Brom says eating snakes is disgusting]
Makes perfect sense in theory, but there must be exceptions - perhaps based on the method of cooking. I've had fried rattlesnake on quite a few occasions and never considered it to be tough.
I think his feelings were hurt - he’s pouting.