Answer:
Although my cow is dead, I still beat her. What a racket she makes!
What stays the same size no matter how much they weight?
I am a good state, there can be no doubt of itΝΎ But those who are in, entirely are out of it.
I can travel from there to here by disappearing, and here to there by reappearing.
Weight in my belly, Trees on my back, I travel fast in my place, but feet is a feature I lack
People take me on walks and I run and have fun. What am I?