>>55360287Here's stuff I keep in mind when designing my fakemon:
Don't simply go "type+animal" and call it a day. You can certainly find your initial inspiration there, but it's very surface level and less memorable if that's all it is. Try to find some other element to make it stand out. You can relate it to another concept (what is sometimes described as jobmon, e.g. a grass/ground sloth that includes elements of a farmer), find some kind of throughline or progression throughout evolution (instead of it just getting bigger, take the concept and expand on it, e.g. a fire lizard with a lava tongue -> lizard drooling lava all over -> entire body is oozing magma constantly). I think stuff like this will help avoid "literally my mom's dog" syndrome.
Pick a limited color palette. Stick to a small handful of colors, otherwise your design will end up looking cluttered.
"It just gets bigger" is the death of evolution. Some easy tips to avoid this is having thematic progression like I mentioned earlier, changing up the general body shape, or changing the color palette slightly (e.g. Charmeleon is a darker red, Wartortle or Dewott are a darker blue, Froakie line becomes progressively darker blue, etc.)
Also make sure they have a recognizable silhouette. You should be able to recognize it at a glance.
Pic related is one of my personal favorites, which I think illustrates these things pretty well.