Monster

Why not change the monstergirl tag to monster and then throw girls getting fucked by monsters in that tag.

Are there many h-mangas with monsters fucking women?

Because the girl being the monster and the girl being fucked by the monster are two distinct things.
People who have a fetish for the monster being the girl, don't necessarily like the monster being on the other end(?)
which is why "monster girl" gets its own tag

perhaps a completely new "monster" tag then? but how much really falls under that umbrella?

tags are made so because it contains something because it is a specific fetish
say.. for example not everyone enjoys every possible form of non-penetrational sex
so we have paizuri and ashikoki...

well... erm.... yeah....
...

monsters gonna monst~

Because usually monster-fucking includes tentacles.

Thus, no real need to deviate from that tag.

because they are so few is why I suggested throwing them into an monster tag that encompasses both monstergirl/monter

And see people raging because MONSTER GIRL and GIRL FUCKED BY MONSTER are two completely different thing?

Because they are so few, that's why we don't put it on a specific spoiler.

too high to even begin to understand that, congrats on the threesome

Shouldn't monstergirl be changed to monster anyways? What if is a monsterboy?

Then no one will care I think.

Like I said, those are different.

Just put "Bestiality" or "Monster Boy" tag when the number of doujins are sufficient.

True.

Off topic: that is the funniest GIF (in your signature) I've seen in a long time for some reason.