Black Seppuku Rabbit

It is Akane's messenger sent by the Generators. Like all the Entrails, it has its ïntestines sticking out, and blood on its mouth.

From what Akane exclaims when she is in her Kampfer mode, it was mentioned that Seppuku has a voice similar to Tamura Yukari.

Obviously, Tamura Yukari is its seiyuu!