Tsk...Tsk...Tsk...I really thought that someone would have some useful advice or information to share. You are all making it too hard on you. You don't need to make your own script, all you had to do was read the essentials note. Poccil already included a dependant events function, which I believe has its own chunk in the notes and even a sample event in the map called Cave1 (with the Brawly fighting event).
All you simply have to do is create an event and set the function pbAddDependency2(@event_id,"Name",2). This will make that event follow you everywhere untill you remove it. It even follows you through maps. So I really don't see the fuss about this "great union for minds to make a caterpillar script for essentials". It will take an event to do it anyways, with this you could either make 493 for each Pokemon, or you could just make a little adjustment and new function in the script DependentEvents, which is what it's basically for. Also you need to notice that the event won't change speed to go faster while running, so you'll need to set a function for that too.
With that said, I really see no point of existance of this thread. That simple question could have been asked in the Essentials Thread. Next time I recommend carefully reading through Poccil's notes, because he included alot of things in his kit that some people havent even noticed.