Gar

The Gar is an fish that can be found in the ponds. It appears from June to September. It will appear from 4PM to 9AM. When selling it to Re-Tail, the player will earn 6,000 Bells.

Location
The Gar is found in the ponds.

The Museum
The Gar can be donated to the museum. Upon doing so, the following text is given by Blathers:

"Their long faces and large mouths make them look like alligators. Some can grow up to three yards. They are ancient fish that haven't changed since they first appeared millions of years ago. They breathe not only through gills, but also by sticking their mouths above the surface of the water. Gar eggs are poisonous, so people all over the world are advised not to eat them -- no exceptions."

Quote
Upon catching the fish, the player will say the following:

"I caught a gar! It ain't gettin' too far!"