I remember reading somewhere on here someone got to operate pepe and said it was just string with a ring on it. I was kinda dissapointed when I read that, cause I always figured muppets had really clever mechanisms.
Anyway, reading this I just came up with an idea so I dunno how well it'd work, but
this is the kind of thing I'd do
Not sure how clear it is, but looking at it now, I also thought maybe you could have string running the opposite way to the trigger through another hole so the trigger always makes a push-pull movement and no need need for a spring.
The trigger would probly need to be bent and ring be slightly further down so it didn't hit your thumb out the other side.
Anyway, just an initial idea. I'd probly fix a few things through trial and error if I was to make this. I already see the hole for the string would need to be more vertical so it didn't start to wear out through the rod.
P.S. I made a simple little cable control puppet already using
this method of operating