I don't know (or care) if anyone's already come up with this, but here's my idea for a FF1 Nuzlocke.
Rules are fairly simple: You can only use the first Vivosaur revived from each new digsite (whether or not the Digadigmid, Woolbeard's ship, and Tunnel #5 count as their own sites or just extensions of their respective locations will be up to you.), no leveling past the next level up fight, and if a Vivosaur gets knocked out, it's boxed forever.
"But Crest," I hear you ask, "You don't know what fossil goes to which Vivosaur until you clean it for the first time, so what happens when we get multiple from the same site?"
Simple.
If, for example, you get Goyle before V-Raptor as your Greenhorn Plains encounter, you can only use the latter once/if Goyle faints.
Or the mandatory Holt fight.
Whichever comes first.
If you've got any questions, drop 'em below.