Koi

The koi is a fish you catch in ponds. Look for a large shadow. In the northern hemisphere it is around all year, from 4 PM – 9 AM. It can only appear after you have caught 20 fish. Nook's Cranny pays 4,000 Bells, C.J. pays 6,000 Bells.

A Large pond shadow from late afternoon until morning, after 20 catches. Carp and catfish share its size, but koi sell for 4,000 Bells, so evening pond trips are worth the effort.