Rainbow stag

The rainbow stag is a bug you catch on trees (any kind). In the northern hemisphere look for it in Jun – Sep, from 7 PM – 8 AM. It can only appear after you have caught 50 bugs. Nook's Cranny pays 6,000 Bells, Flick pays 9,000 Bells.

A colourful stag beetle on any kind of tree on summer nights once you have 50 bug catches. Creep in with A held, then sell it to Flick for 9,000 Bells.