Kṛṣṇa comes personally to canvass that "This is not your proper order of life. You are misusing your independence for sense gratification and wandering through various types of transmigration of bodies—sometimes human body, sometimes dog's body, sometimes cat's body, sometimes demigod's body, sometimes rich body, sometimes poor body. So you stop this business," Kṛṣṇa says. Sarva-dharmān parityajya (BG 18.66).
"You have manufactured so many duties. That duties means you are manufacturing so many bodies. That's all."
Why you have got different types of bodies? We have manufactured it. God has given us facility. I wanted to become such and such. He has given us facilities, "All right, you become such and such." If I want to become a tiger, God will give me all the facilities to become a tiger. He will give me facilities, paws and nails and teeth, so that immediately I can capture any animal, and with the instruments which He has provided within my body, I can immediately scratch it into pieces and eat.