Everypixel is a AI powered search engine for photos.
Everypixel will search 50 online photo repositories and find photos based on what you asked. The AI seems to be pretty good, except on a search for kitten one of the results was this:
There isn’t a safe search option, and in my testing, a few obvious searches for inappropriateness brought up some pictures that would definitely give me pause in a school setting. I don’t know if that’s supposed to make you feel better or not, so if you have students using the site, keep an eye on them.
Also, the site doesn’t require a log in.