OK this is Nils from the future. Sadly this command broke in 1.14 because they did some changes that lead to my villagers changing their profession as soon astray get spawned, wich means that you will no longer be able to reach the trading results UNLESS, you spawn them in, in 1.13.2 and save the trades in saved toolbars.
Here is young me:
I just spent 2 hours to make a pet shop... whats wrong with me.
This command allows you to spawn 2 new pet into your Minecraft 1.13.1 world!
Pet number 1 is the dwarf. The dwarf is a cute and green dwarf that will... uhhm? Follow you? Hope that is exiting enough.
Pet number 2 is the muted beast. As you may know the beast will be added in the Minecraft Village and pillage update. I ran out of ideas so I created the mutated beast.
I can't get rid of the other trades appearing after you trade with the villager.