In my efforts, I needed to list a few random insect species with their order, family, weight and image. The following command causes EntityValue[] to crash/timeout and then the system says it is downloading all 490,000 values/insects (followed by 490K+ more values):

({#, #[{"Order", "Family", "Weight", "Image"}]} & /@ 
  RandomEntity[EntityClass["Species", "InsectSpecies"], 20]) 

or

Map[Function[ aSpecies, {aSpecies, 
   aSpecies[{"Order", "Family", "Weight", "Image"}]}], 
 RandomEntity[EntityClass["Species", "InsectSpecies"], 20]
  ]

The output looks like this:

This happens consistently. I waited 15 minutes for the first 400K+, then I $Aborted.

Also the same command runs quickly (i.e. downloads very few values) and correctly when run with:

MammalSpecies, or

CrustaceanSpecies

Any help is appreciated.