Stranded Aliens

Lol at least you can tell the tagging system is working.

Maybe the Aliens were able not to evolve but to geneticallymodify themselves to fit the planet better. Then the already fluid DNA could have been exposed to some sort of environmental trigger that caused mutation into Chups? Bigfeet? Mothmen? Jersey's?

First off no one knows if any of these monsters really exists. Secondly what if aliens aren't like the greys at all. i mean as stories of reptillians grew so did sightings and abductions which means how accurate is the information we receive from eye witnesses and victims etc.

As for evolution it takes a long time to evolve but over time or even genetic modification it coyld be acheived.