How do you make mobs follow each other in a trail?

I am trying to make a new mob for part of a big project but the problem is that I can't figure out how to make mobs follow eachother... I was going to make it so that I have 3 zombies... Ones the lead and another is following behind... The third zombie will be following that one... Is this even possible? Help would be really appreciated

Solution 1:

You could use a similar method to what SethBling used in this video – get each zombie to start tracking a villager (by allowing each zombie to hit its own villager once), then teleport each zombie's villager to (slightly above or below) where you want it to pathfind to (e.g. above the next zombie in the line).