WaruSeadramon

WaruSeadramon is apparently the corrupted form of MegaSeadramon, and it never appeared in the show, however it appeared in Digimon Card Battle.

Digivolution

 * Baby, unknown
 * In-Training, unknown
 * Rookie, Betamon
 * Champion, Seadramon
 * Alternate Champion, Airdramon, but Airdramon doesn't Digivolve further.
 * Ultimate, Mega Seadramon
 * Corrupted Ultimate, WaruSeadramon, but digivolution ends there.
 * Mega, MetalSeadramon

Attacks

 * Poison Wave
 * Dark Blast