Battikaroa

Battikaroa is a giant Hollow that has some abilities as an Arrancar that has a similiar appearance to that of Runuganga.

Appearance
Battikaroa is almost identical to Runuganga in every way except for the protruding spikes around his neck and more on his crown as well.

Fake Karakura Town arc
He battles against Renji Abarai and Yasutora Sado while they are fighting hordes of Hollows below the fifth tower. At the beginning of the battle, Renji tries to attack the mid-section of Battikaroa. This does not work as his sword is almost swallowed by the Hollow. Sado saves Renji's sword by helping to pull it out. Eventually, Sado tries to use La Muerte on the Hollow, which is able to cause a crack up that runs up to a location right below the mask, but the Hollow hits Sado off before it cracks the mask. Eventually, they figure out that Battikaroa has one weakness; his head. After numerous failed attempts at breaking the mask, Sado attacks with his La Muerte technique, which hits Battikaroa's bottom. While it's preoccupied with Sado, Renji fires a Hikotsu Taiho blast at the Hollow's mask, defeating him.

Powers & Abilities
Unhinged Jaw: Battikaroa has the ability to widen his jaw to such a size as to swallow the entire group of his opponents in one fell swoop.

Cero: Battikaroa can also open up his mouth incredibly wide and fire a large standard red colored cero. It has quite an explosive knockback

High-Speed Regeneration As long as his mask is not destroyed, Battikaroa can restore his body, very similarly to Runuganga

Enhanced Strength: Battikaroa's punches are shown to have incredibly high knockback, being able to hit Yatsutora and Renji very long distances