Many of these answer to opponents instants
You might well have seen one or two of these creatures in the past and not realized that theyre usually part of a cycle, with one in each color
It seems like theres a general push to make cheap version of every card someone might need as a game piece to stop entry into the game from becoming prohibitive and a realization that expensive cards can always be created through premium versions
But a 'walker is often a lot harder
The result is surprisingly similar to what you get from Dromoka, the Eternal, but the color pair aligns better
Anything that makes a decent proxy or casual replacement, whether its an expensive card like the CLB metallic dragons, a basic land, a Sol Ring, or even a beast token can have some trade value