Human Hybrids of Shaggai

The Shaggai are basically Shan "Deep Ones". The Shan interbred with humans—somehow—the result of which grow up human until adolescence when they start developing insectoid traits, eventually becoming a full Shaggai.

In the RPG...

There are a few creatures like this in Call of Cthulhu, whereby a human grows to adolescence (or later), seemingly normal, only to transform into a monster. Deep One Hybrids are the most well-known example, but there is also Petesouchi, as well as the many children of the gods, such as Spawn of Ithaqua, Spawn of Nyogtha, and Fosterlings of the Old Ones. While I didn't mention it in the Ghoul entry, the story they come from, Pickman's Model, mentions changelings who are raised as humans before turning into Ghouls later in life as well. I really like this concept, narratively. Especially if the person doesn't know they are a monster.

    The Shaggai don't retain the phasing abilities of their ancestry. The only unique attack they have is that their proboscis can spit acid acid, which not only takes hit-points, but also APP. It also continues to decrease both of these stats until washed off. For added effect, the acid can also eat through most materials, taking armour points instead of hit-points.

    As far as stats go, Shaggai have mostly human averages, though they are less educated and smaller—perhaps because they are still teens before their metamorphosis. Shaggai Queens have increased CON, INT, POW, and even EDU, but are smaller again. This means they have a 28% chance of being smaller than the smallest adult. Transformed Shaggai still have human-ranged stats, though the Queens have CON and DEX well above the highest human. Strangely, despite Queens having -10 SIZ as humans, they then go on to have +10 SIZ as Shaggai. Perhaps this was a typo, because in the paragraph on Queens, it says, "Queen shaggai are stronger and more intelligent, although they are usually smaller."

    Almost every stat has been changed for the 7e Malleus Monstrorum, so I'm not going to worry about comparing them. Just know that they are different.

In a video game...

With near-human stats, I think the Shaggai would actually be pretty cool in a video game. They do have 4-point armour, so would be slightly harder to kill, but not impossible by any means.

In a film...

Humanoid insects—or insectoid humans—have the potential to be either really cool and scary, or completely laughable. It would be a fine line that would require the right director and FX team.