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Krebbs is an operations manager and sensor operator on Leiter's destroyer. He is responsible for detecting the Vipers of Apollo and Starbuck that are escorting Michael's ship to Paradeen, and is a part of the ground force that storms Paradeen (Greetings from Earth).
He is also incarcerated on the Prison Barge, until they escape thanks to the assistance of Borellian Nomen Maga, Taba, and Bora, as well as the treacherous Lord Baltar. He presumably goes back to the Eastern Alliance controlled Lunar colony, along with Leiter and the Nomen (Baltar's Escape).