[RMVX ACE] A DOG SCENT TRAIL?

The best I got is making a looping animation that plays itself on a series of events tiles when in dog form.

If those tiles lead to where you're following your nose to, I think you've accomplished your goal already! I mean, what I was going to advise wasn't even that fancy, it was just lighting up some events with a graphic when you're a dog and they're leading to where you want to go (which requires only the coordinated use of two switches, dog switch and different switches for "objective x", objective y, objective z" and and maybe have the tiles disappear when you move over them via self-switch (or regular switches if you want to be able to reappear them later easily for whatever reason). That works perfectly well as a trail of breadcrumbs. JustAShyDoge taught me something similar with the waypoints he made for the second half of WYWY, but those were for the world map.

In any case: this does not seem like a system that really requires a script (although I wouldn't bet against there being a script for it out there, I don't know of one).

My dog spends a lot of his time leading me whilst sniffing the ground but has never lead me to a quest objective or a treasure (that I wanted; dogs have very different ideas about what constitutes "treasure" and your game should totally have at least one of these scent trails lead to like a gnawed on bone from an unidentifiable animal or a pile of reeking garbage, because that my friend is what dogs are really after).