The Malgorian was a two-headed creature known for its inability to make up its mind.
In 2369, Mullibok compared Major Kira Nerys to a two-headed Malgorian because she was divided about the forced removal of Bajoran farmers from Bajor's fifth moon, Jeraddo, so that its core could be tapped as an energy source. (DS9: "Progress")
The way Mullibok consistently referred to the individual as "a two-headed Malgorian" might suggest not all Malgorians were two-headed.