- The subject of this article is sometimes romanized as Suu.
Su is solid white with squinted eyes and average sized ears. Her mouth somewhat resembles a snout and has never been shown open. Her tail is long compared to her body, and is lighter at the end.
Su seems to like pumpkin juice, as she drank some that was left unattended by Pagaya. She also seems able to sleep in loud situations, as she slept through Pagaya and Conis' meeting with Nami and wasn't disturbed by Pagaya's loud music.
Su seems to love Conis, as she is frequently seen in her arms or by her side. Su is also seen comforting her owner. Conis also trusts Su, as she left the cloud fox in charge of watching over Sanji and Usopp.
Pagaya seems to trust Su, as he left her in charge of keeping watch. Su, however, seems to get frustrated with Pagaya. When she tried to warn him of someone approaching, Pagaya thought she was hungry, much to Su's agitation.
After the Straw Hat Pirates arrived on Skypeia, Su approached the crew. As Zoro asked what the creature was, Conis, playing music, introduced herself and Su to the crew. Su watched as Luffy and Nami tried Conis' Waver and followed them back to Conis' home for dinner.
While the Straw Hats were fighting in the Upper Yard, Su sat next to Conis as she, Pagaya, and Gan Fall discussed the island's current situation. Su was also seen drinking some of Pagaya's pumpkin juice.
Su was later seen riding with Pagaya, Conis, and Aisa in Pagaya's dial boat. By the time they met up with Nami, Su had already fallen asleep. Su awoke soon after, as she was seen on the deck of the Going Merry.  After Nami and Aisa left, Pagaya asked Su to keep watch on the ship. When she saw someone approach, Su began calling out loudly, gaining Conis and Pagaya's attention. After Pagaya was attacked by Enel, Conis left Su in charge of watching Sanji and Usopp who were healing below deck.
While Conis was gone, Sanji and Usopp recuperated and decided to help Luffy fight Enel. Su tried to convince them not to go, but her efforts did not stop them. When Conis returned, she Su in a worried state, trying to tell her owner of their departure. Su calmed down with Conis' return. She was seen in Conis' arms when Enel began to destroy the island. She was also seen trying comfort Conis, who blamed herself for endangering the Straw Hats by getting involved in the affairs with Enel. Conis confided to Su about her desire to be saved by Luffy and his crew. Su was seen in her owner's arms once again when that desire came true
As the Straw Hat Pirates prepare to leave Skypeia, Su, Conis, and Pagaya see them off.
- She is named after the "Su" sound she makes. Whether or not this is unique to Su or a trait of all cloud foxes is unknown.