Zu-Gumun-Ba

Zu-Gumun-Ba (voiced by Tetsuo Sakaguchi) also known as Unidentified Life Form #1 (未確認生命体１号 Mikakunin Seimeitai Ichigō) to the police, is the first of the Gurongi to appear. Gumun first appeared in southern Nagano weaving a web on the 1532 MK Building, overwhelming law enforcement as he attacks them without mercy with his power to spray webbing and create claw extensions on his hands.

Crashing into the police station, Gumun slaughters the police officers until Yuusuke puts on the Arcle, being targeted by the Gurongi as he becomes Kuuga in "Growing Form" in a fight that ends with Gumun being knocked out of a helicopter several feet in the air.

Surviving the fatal fall, Gumun reappeared to settle the score by aiding Gooma in his clash with Kuuga, now in his Mighty Form. But in the end, the Zu was mortally wounded by Kuuga's incomplete Mighty Kick, screaming his intent to kill Kuuga as he exploded.

At least one Zu-Gumun-Ba was part of a group of human-turned Gurongi created when they were exposed to N-Gamio-Zeda's miasma. Some were later absorbed by him in a last effort to defeat Kuuga and Decade. The remaining Gurongi died after Gamio was defeated.

Zu-Gumun-Ba was one of two Gurongi seen on the front page of a newspaper detailing the appearance of the Unidentified Life Forms that was read by the Hikari Studio group when they arrived in the World of Agito.

Zu-Gumun-Ba's destruction at the hands of Kuuga (as seen in Transformation) was shown in a recollection by Amadum as he explained the nature of his world as a paradise for monsters destroyed by the Kamen Riders.