>Go to https://www.bing.com/images/create
>SEARCH "Intelligent species that lives deep underground"
Don't put anything about aliens, reptilians, or any specific descriptors like that. That will taint the result. Just use the word "intelligence", and the location you believe it to live. You could also try "nonhuman intelligence", etc, just don't use any specific descriptor of a known alien race. Notice how it keeps making things with elongated heads, like the Mexican mummies revealed in Mexico?