Here are two aliens, a Grey and a Frot. Do you think Greys could be an artifiticial subspecies of the Frots, and if so, what would have to be changed in their biology? (Frots are amphibians)

Here are two aliens, a Grey and a Frot. Do you think Greys could be an artifiticial subspecies of the Frots, and if so, what would have to be changed in their biology? (Frots are amphibians) picture 1 of 1