From Zelda Legends Wiki
An enemy resembling a fish skeleton. Jumps out of the water (or lava, as the case may be) and shoots fireballs.
|| Appearance: AoL|
Habitat: Bridge Sections
Quick Facts: Bago-Bago comes in two varieties. The first and one is found on the bridge to Death Mountain Area. The other and more dangerous type is the Red Bago-Bago which appears only on a few bridge sections in the Great Palace.
Attack Pattern: Bago-Bago usually jump out of the water (or lava) trying to hit Link. Sometimes they will pursuit him over the bridge as well.
The skeleton fish Bago-Bago is a very annoying enemy in AoL. It may not be very strong, but if they make contact with Link they will steal 20 Exp from him. The regular ones only give 3 Exp so it is quite meaningless to fight them; one touch means about 7 extra kills. Also Bago-Bago will shoot with little rocks to hit Link from a distance. The best method is to run over the bridges fast avoiding as much of this fish as possible. On the bright side they only appear on the bridge from the town of Saria to Death Mountain Area.
The stronger version is the Red Bago-Bago. These critters appear in one of the last sections in the Great Palace. Instead of rocks they shoot fireballs which means you need your magic to protect yourself against these attacks. They drop a little more Exp., but it is still not worth fighting these.
Bago-Bago looks a lot like the Skullfish found in Majora's Mask, although there is no connection between them. Their appearance is almost identical to that of a Bago-Bago.