Shawlong Kūfang, the Undécimo (11th) Arrancar, was the leader of Grimmjow's five Fracción and was also believed to be the oldest living Números.
Shawlong Kūfang was once a Gillian-class Menos who had been born into existence with a personality, a trait rarely ever found in Gillians, and spent much of his existence cannibalizing his fellow Gillians in order to further his evolution. Eventually he grew to become an Adjuchas-class Menos and began reaching higher in an attempt to evolve into a Vasto Lorde.
Shawlong became the leader of a group of Hollows (primarily Adjuchas-class Menos) consisting of himself, Di Roy Linker, Yylfordt Granz, Edrad Liones, a Gillian named Nakeem and two other unnamed Adjuchas and together they set out on a quest to better themselves through the consumption of other Hollows and evolve into Vasto Lordes.
During the course of their journey, Shawlong and his fellow Hollows encountered a tiny Adjuchas who called himself Grimmjow. Following a small dispute between Grimmjow, Di Roy and the two unnamed Adjuchas'; Shawlong, who was impressed by Grimmjow's display of sheer power asked for him to join with them as their King.
However, what they failed to realize was that when a portion of a Hollow's body is consumed, his evolution stops right there and then making it impossible for them to go any further. When he learned of this fact, Shawlong and the others decided to give up in their quest to evolve into Vasto Lordes.
The reason for this being that Shawlong had come to believe that they were never destined to evolve into Vasto Lordes, that their ultimate destiny had only been to reach the status of Adjuchas. Grimmjow snorted in disgust at Shawlong's announcement and decided to detach from the group.
However before he left Shawlong asked if Grimmjow would "eat" them in order to completely halt their evolution as well as erase the possibility of them de-evolving back into mindless Gillians, Grimmjow did so and they parted ways. Years later however Shawlong, Di Roy, Yylfordt and Nakeem were reunited with Grimmjow after being turned into Arrancar and became his Fracción.
Shawlong was first seen when Ulquiorra Cifer and Yammy Rialgo returned from a reconnaissance mission in Karakura Town under Sosuke Aizen's orders to retrieve information on Ichigo Kurosaki.
When Grimmjow and Shawlong learned that Ulquiorra and Yammy had not killed Ichigo, both of them commented that Ulquiorra had made a serious error in judgment and that Ichigo was too powerful and too dangerous an adversary to simply ignore and let live.
Later that night Shawlong, Di Roy, Yylfordt and Nakeem met up with Grimmjow on Earth and launched the second invasion of Karakura Town in order to finish what Ulquiorra had started.
Using their abilities to scout out those with strong spiritual power Shawlong and Nakeem ended up crossing paths with Tōshirō Hitsugaya and Rangiku Matsumoto whom they engaged in battle, with Shawlong taking on Tōshirō.
During their fight, Shawlong explained to Tōshirō how the Arrancar ranking system worked and revealed that Grimmjow was the Sexta (Sixth) Espada and then easily overwhelmed Tōshirō afterward despite the fact that Tōshirō had released his Bankai.
Shawlong later took notice of Yylfordt releasing his Zanpakutō and then proceeded to do the same while stating that it would be an insult to Tōshirō if he simply waited for his Bankai to run out of power and then killed him outright.
Though it seemed initially as if Shawlong was going to end up winning the fight, the limiter on Tōshirō's Bankai ended up being removed, allowing Tōshirō to fatally wound Shawlong and entomb his corpse in a block of ice.
Shawlong is extremely proficient in the use of his Zanpakutō and with it, he was easily able to fight off and nearly kill Tōshirō Hitsugaya while his Bankai was operating at 20% of its maximum power.
Shawlong was seen using Sonído frequently during his fight with Tōshirō Hitsugaya.
Shawlong is the oldest of the Números and as such is one of the most intelligent Arrancar to have ever lived. Shawlong was instantly able to realize what the limit on Tōshirō Hitsugaya's Bankai was and knew very well how to counter his attacks.
Shawlong's Zanpakutō was known as Tijereta (五鋏蟲 (ティヘレタ), Tihereta; Spanish for "Earwig" and Japanese for "Five-Pincered Insect") and while sealed it looked like a standard katana with a guard that was shaped like an oval with a gap going down the middle and hollow corners.
Once Tijereta is activated by the release command "Snip", Shawlong grows armor that covers his arms and upper chest, his hands transform into long claws and his mask extends down to completely cover the left side of his face. The mask fragment which extends out to his right becomes a claw-tipped tail.