It's a pretty popular tag in other boorus. If someone want to search for post of humans and pokemon in sexual acts, they would have to search for either "interspecies pokemon_(creature)" or "bestiality pokemon_(creature)", or a mix of the two "~interspecies ~bestiality pokemon_(creature)". Different searches with multiple tags for a single and simple concept that could be a tag alone. Interspecies work for humanoids, while bestiality for animal-like, but some Pokemons are kinda in a thin line between the two so it can be hard to define sometimes. That's why a tag like pokephilia could be very useful.
If more users agree, I would create this BUR:
mass update interspecies pokemon_(creature) -> interspecies pokemon_(creature) pokephilia
mass update bestiality pokemon_(creature) -> bestiality pokemon_(creature) pokephilia
imply pokephilia -> pokemon_(creature)
Thoughts?