Swamp Rat, Steven and Cydne are the antagonists shady used-goods dealer in 101 Dalmatians: The Series, Swamp Rat is the main antagonist was voices by Jeff Bennett, Steven is the secondary antagonist and Cydne is the tertiary antagonist was voiced by Frank Welker.
While they aren't a major threat in every occurrence during the TV series, they pose as threats more often than not.