Siren Yu Bianfu

Siren Yu Bianfu, also known by his English-translated name Private Jade Bat, is the secondary antagonist of the SpongeBob & Sagwa series from Season 1 to the first half of Season 2. He is the right-hand man of Yu Bianfu-Wang and commander of the Jade Bats.

Like SpongeBob, Gary and the French Narrator, Siren is voiced by Tom Kenny.

== Appearance == Siren appears as a small green bat with long upper fangs, hair locks, bushy eyebrows, an overweight stature and a busted soldier helmet.

== Personality == Just like the other Jade Bats, Siren is always proud to follow Bianfu-Wang's orders in order to help him satisfy his evil deeds. However, since the episode Siren's Unlucky Flight, he began to lose his sense of vigilance and optimism and started to become incompetent, just like Bianfu-Wang himself.