This page uses data from the Miitopia Param Info spreadsheet, compiled by PibPasquale, Kobazco, and UglyFrenchFry.
Forest Nuts ★★ are a mixture of cashews, almonds, walnuts, pistachios and possibly other nut varieties placed in a large brown bowl with a tan rim and triangle pattern. The triangles on the bowl are much thinner than the ones on the bowls of Forest Nuts and Forest Nuts ★. A few nuts seem to have fallen out of the bowl. The color scheme of the Grub, particularly of the bowl, may be based on the "Eldest Fab Fairy" Owl.
(Has sparkles, only V. Rare foods have this.)