Napoleonfish

The Napoleonfish (ナポレオンフィッシュ, Naporeon Fisshu) is a big, blue, rare fish with a large humped head. One of a group of fish which all sell for 10,000 Bells, this fish appears during late summer in the sea and island sea. Like most other sea fish, the Napoleonfish appears in the back tank, when placed in the museum. Its first appearance is in and it also appears in  and.

In
Upon donating the Napoleonfish to the museum, Blathers will comment:

"Hoo, my good gracious! What size! What majesty! What impact this fish has! When fully grown, the body of this fish can reach a length of over 80 inches, eh wot? The beady eyes and pouty mouth make it appear a bit dull witted...which I find rather charming!"

The Napoleonfish can be found lazing around near the bottom of the sea fish tank at the back of the fish exhibit.

In
After donating a Napoleonfish to Blathers, it will appear in the section for fish and sea creatures, specifically in the large tank in the northeastern room of the fish and sea creatures area.

The exhibit has this to say about the Napoleonfish:

"Called Napoleonfish, these fish also have the more accurate name of humphead wrasse. The true name comes from the distinctive humps on their heads. But "Napoleonfish" is more popular. When small, all Napoleonfish are females, but some become males as they age and their humps grow. Their bodies also turn a bluer shade as they mature and become males, making identification simple. Their bulky bodies, which can get to about six feet long, still glide easily through warm tropical waters. Finding these fish is a real treat for divers, as they're stunning to see-- and it's a great story to tell."

In
Blathers will say this when given a Napoleonfish:

"Quite the catch you've brought! The stately and debonair Napoleonfish is truly something to behold. Those beady eyes! That bumpy head! That bold blue-green coloring! Alas, this quirky creature is quite endangered due to a variety of factors. Needless to say, we must do our very best to take care of our lumpy friend and its environment."

Real-world information
The Napoleonfish, Cheilinus undulatus, is more commonly known as the humphead wrasse; both names are derived from the large hump on the forehead of adults. Males are larger than females. Due to overfishing and the destruction of coral reefs, their natural habitats, the fish is now considered endangered. Humphead wrasses are protogynous hermaphrodites: all fish are born female, but contain the genes for both sexes, and some fish change sex to male a year or two after sexual maturity.