I noticed there is an 'anthro_penetrating_anthro' but the related 'non-anthro_penetrating_anthro' seems to be MIA. Am I just typing it wrong or is it missing?

Try feral_penetrating_anthro, human_penetrating_anthro, humanoid_penetrating_anthro or taur_penetrating_anthro, instead.

Roseroar said:
I noticed there is an 'anthro_penetrating_anthro' but the related 'non-anthro_penetrating_anthro' seems to be MIA. Am I just typing it wrong or is it missing?

It's not so much missing, as considered too vague to be a useful tag. You need to use one of the more-specific tags Clawstripe mentioned, instead.

@Clawstripe Oh! Cool! Ok. Thanks! :D