Crawfish

The Crawfish (ザリガニ, Zarigani) is a common crustacean found in the Holding Pond between the months of April to the middle of September, found at any time of the day. It is worth 250 Bells.

In Wild World
"You'll find these little fellows in many pots across the southlands, I imagine. I've personally never sampled one. They look rather... insect-ish. Blech."

In City Folk
Upon donating the Museum, Blathers will talk about the Crawfish;

"...I don't do particularly well when around crawfish. I mean, really. Look at it. It's like a wretched insect! And those legs... Did you notice all those wiggly legs? All the better to revolt me. Hoo, and the vulgar belly, all segmented and buglike. Absolutely abhorrent!"

It can be found in the middle-left tank in City Folk.

Encyclopedia Information
Once the player has caught a particular fish or bug, they can find information about it in the bug or fish menus. Once the crawfish has been caught, the following information can be found in the fish menu:

Further Information

 * The crawfish featured in Animal Crossing (Procambarus clarkii), is a member of one of the three largest freshwater crawfish. There are other names other than crawfish, such as crayfish, crawdads, and crawldads, known around the world in their respected territories.
 * In reality, you would have better luck finding these crabs in a creek or small, shallow river.
 * Crawdads are used in Louisiana's famous French Quarter as food.