Triffany will ask for you help locating secret in Bugsnax. This will mean revisiting for of the earlier places in the game and finding very specific items that she is interested in. It will often mean catching a specific Bugsnack as well.
In Flavor Falls, Tiffany wants you to find a Stony Grumpus and scan it. This is not out in the open, and can be a little tricky to find.
When you arrive in Flavor Falls, turn right and walk towards the river.
From there, walk up the river and you will see a cave on you right side.
Go inside the cave and walk to the end of the ramp and you will see the Stony Grumpus on the right. Take out your scanner by hitting the right thumbstick and scan it for her.
You can also find another item that Triffany wants in this cave, a Pinkle. To catch a Pinkle you will need to take out the Snak Grabber and use it to pull off the Pinkle’s protective jar. The little green Bugsnack will then run around the area. Drop the jar and run towards the Pinkle, then hit Square to catch it in your net.
Return to Triffany and feed her the Pinkle, then talk to her about the Stony Grumpus that you scanned and this portion of her quest will be complete.