Zedams, aslo known as Alfroids, are batracian humanoid aliens who developped a spacefaring civilisation. Toward the end of the twentieth century, they were at war with the Keema. Zedams have a huge froglike head, webbed hands and feet and are probably amphibious. They are known to wear long robes and jewelry.
The only recorded contact of a Zedam with mankind was with a family of space explorers stranded on an alien planet where the Zedam leader was to meet the Keema leader in a duel whose winner would win the war. From the sayings of the Zedam leader, though, it was clear that he knew much about Earth and had probably visited it.
Zedams are able change their appearance but the nature of this ability is not known, although, as Keema can do the same, it is probable that this is the result's of each culture mimicking the discoveries of the other to better thwart them.
Zedams are known to use short range teleporter technology and spaceship mixing mechanical and vegetal elements.
Source: Lost in Space, The Golden Man (The term Zedam is used one time in the episode and its orthograph is approximative.) In "The Galaxy Gift", where the term Alfroids is first mentionned for the species name.