Atlas moth

The atlas moth is a bug you catch on trees (any kind). In the northern hemisphere look for it in Apr – Sep, from 7 PM – 4 AM. It can only appear after you have caught 20 bugs. Nook's Cranny pays 3,000 Bells, Flick pays 4,500 Bells.

A big moth that rests on the trunks of any kind of tree at night, rain or shine, once you have 20 bug catches. Sneak up with A held so it does not flutter off, and Flick gives 4,500 Bells.