Pets,Bodyguards,Monsters,oh and Girlfriends {Custom Mobs} by ibreak_neo

First off you need a mob to replace it could be Wolf,Zombie,Ocelot,more

Second do this command "/summon armor_stand ~ ~ ~ {NoBasePlate:1b,ShowArms:1b,CustomName:"(Custom Name Here)",CustomNameVisible:1b}"

The " is Needed in the CustomName part

And if you want it To be small just add "Small:1b" there should be a "," if you put it next to another DataTag

Third you need to summon your Mob then paste this command on a repeating command block "effect @e[type=(mob Here)] invisibility 2 1 true

you could add more effects if you'd like to

Fourth Customise your Armor_stand with anything

"Go to minecraft-heads.com to get heads"

then get another repeating command block

paste in "tp @e[type=armor_stand] @e[type=(mob Here)]"

oh and if you'd like to name your Custom Mob change the "@e[type=armor_stand]" to "@e[name=(Name Here)]"

if you are in an Overworld then do the same thing to the mob change it to "@e[name=(name here)]" because it won't work because there is a lot of mobs in the 

Overworld

then that's all thank you and goodbye