Animal Species/Sky Island Saga

South Bird
Found on Jaya, the South Birds (サウスバード,) are strange looking birds have a freak habit of always pointing their head south, no matter where they are (much to the amusement of Luffy). In fact they find it most uncomfortable to point in any other direction. As a result people use them as compasses since Log Poses don't work except to point to the next landmass and normal compasses don't work on the Grand Line. They have a loud call that can control bugs. They first appeared in Chapter 230 and Episode 149.

Insects

 * Tarantulas (crawled onto Nami and fell from trees)
 * Moths
 * Centipedes
 * Giant Centipedes (killed by Zoro)
 * Atlas Beetles (considered idols to some people of the world) and another one called Miyama. Luffy finds a Hercules Beetle (the second idol beetle) in the way back from his fight with Bellamy.
 * Bees (Southbird dropped a beehive in front of Luffy and Chopper)
 * Giant Mantis (chopped a tree down and chased Luffy)
 * Seven Star Ladybugs (huge lady bugs that rolled downhill nearly crushing Nami, Sanji and Usopp)
 * Giant Beetles (they stand as tall as Zoro and stand in his way)
 * Giant Slugs (twice as tall as Sanji)
 * Fireflies
 * Cockroaches
 * Though they are not insects, South Birds could also command Boars/pigs.

Giant Mantis
Giant Mantis are mantis with the size of a man. One of them tried to kill Luffy and Chopper while they were searching for the South Bird. While searching for Bellamy who has stolen Montblanc Cricket's gold, Luffy managed to get his revenge on the Giant Mantis. It first appeared in Chapter 231 and Episode 150. In the anime, a similar kind of mantis has been shown in Impel Down, in Level 2's Beast Hell.

Skypiea
There are many creatures around the Sky Islands, however, most are not named in neither the Manga nor the anime.

Cloud Fox
The Cloud Fox (雲ギツネ) is a small cute white fox creature found in Skypiea with a long snout. Su is the name of cloud fox owned by Conis. It first appeared in Chapter 239 and Episode 154.

Giant Python
A giant species of snake that are native to Upper Yard of Skypiea and Jaya. They were worshiped by the Shandians as a God. It is assumed there are very few due to their large size. Characters often reference Nola, the only known living giant snake seen and aside from her mother (Jaya) and grandmother (Kashigami) no other individuals are shown.

Notably, there are no males seen. This means that either the males died out after or just before Nola was born or they reproduce through "Parthenogenesis" type reproduction. Nola herself appeared to have no offspring making the latter less likely.

Sky Fish
Sky Fish (空魚) are fish who live in Skypiea. They have evolved to become flat or inflated like a balloon so they would be light and could live in the clouds around Skypiea. Some of them grow very large. There are different species of Sky Fish. Some are rare and their capture is prohibited. They first appeared in Chapter 237 and Episode 153. Sky Fish appear in One Piece: Unlimited Cruise, in which they can be fished in the clouds.

Sky Shark
The Sky Shark (空サメ) is a type of stranger looking flying shark that inhabits the areas around Upper Yard. They are vicious, attacking anything they can reach without hesitation and will even devour other sky sharks that have been wounded. They first appeared in Chapter 245 and Episode 159.

South Bird
Also found on Skypiea as well as on Jaya island, the South birds here however are much larger then those living in the blue sea and seemingly much friendlier (perhaps even too much). This variety first appeared in Chapter 230 and Episode 149.

Speedy Shrimp
Speedy Shrimp (特急エビ) are giant shrimps who takes ships stationed near Heaven's Gate into the sky islands of Skypiea. They first appeared in Chapter 238 and Episode 153.

Super-Express Speedy Shrimp
Super-Express Speedy Shrimps (超特急エビ) are gigantic shrimps twice the size than the average Speedy Shrimp. They take any ship with its crew onboard to the Northeast portion of Upper Yard so they can be sent to the Sacrificial Altar. They first appeared in Chapter 243 and Episode 157.

Octopus Balloon
Octopus Balloon (タコバルーン) are octopus that live in the White Sea of Skypiea. They are a common animal in Skypiea and are also one of the most fragile. These animals can also be used as aerial transport, when they intake enough air they can become as light as a feather. One was used by the Straw Hat Pirates to take their ship down from Skypiea. Without being inflated they are only three feet tall. Apparently they can still move in the Blue Sea, unless they float back up to Skypiea. They first appeared in Chapter 302 and Episode 153.

Cloud Wolf
Cloud Wolves (雲ウルフ) are wolves living at Upper Yard. They are tamed wolves. They partied with Luffy and the Straw Hat Pirates. A normal man would probably see the wolves as fearsome due to the fact that they are obviously predators in Skypiea. As numerous other animals in One Piece, these animals have the ability to walk on two legs. They first appeared in Chapter 253 and Episode 166.

Sky Eel
Sky Eel (空ヤツメ) are giant eels that lives in Upper Yard. Sanji managed to defeat one when it was about to eat him, Luffy and Usopp. They first appeared in Chapter 246 and Episode 159.