Rideable Mobs In Vanilla minecraft - One command

Hello guys!
I created a new redstone concept. With this concept you are able to ride 4 new mobs: slimes, cows, sheep and (of course XD) mooshrooms \('')/. It's nothing to special, just click the sign on the machine to get the 4 spawn eggs you can use to spawn the rideable mobs. This concept isn't made for your survival world or something, that's why I didn't include custom crafting recipes. The concept is completely finished but I'm not quite happy with some things. For example the slime damages you when you ride it in survival or adventure mode. To solve this problem you get a extremely high resistance effect when you are riding it, so you don't take any damage. But you still hear the hit sound and your screen is shaking :/.
Copy the command from pastebin.