I've been working on making like an entire Fakemon region based on MSM. Was planning on revealing it with the starters but I'm still thinking of ideas for what animals Kayna and Potbelly will be soo have this
Monstronian Poliwag, Water/Rock type. Most Poliwag in Monstronia tend to live inside caves, so they've evolved to have small horns made of a pink crystal, which can glow whenever the Poliwag wants. The pattern on its belly shows the Soundwave of the Poliwag's speech, and can glow as well.
Monstronian Poliwhirl, Water/Rock type. Although they lack the mouths they once had as Poliwags, they can still speak, though it does come out a bit muffled. Luckily, Monstronian Poliwhirls are very good at interpreting soundwaves- although tone can sometimes be lost in translation.
Poliwhail, Water/Rock type. Although, at first glance, it may seem like they lack a mouth, that's far from true. The belly is actually a large jaw! Although the soundwaves and crystals do still glow, they no longer need to, as the three eyes of the Poliwhail are now used for seeing in the dark. Instead, Poliwhail will use the crystals to attack.
Too lazy to make colored versions rn but meh
Poliwag is orange, Poliwhirl and Poliwhail are green. Shiny Poliwag is yellow, and shiny Poliwhirl and Poliwhail are purple, with all three having blue crystals
