I went ahead and recolored the weird-colored ones to make them easier to see:
Now, with that done, I'll go ahead and comment on a few of them. I won't comment on all of them, just a few.
First row, third column: This looks slightly like a Sudowoodo with the tree and the three branches with leaves. Not completely the same, but I see a bit of a resemblance.
Second row, first column: This one looks like a caveman. This made me laugh.
Second row, fourth column: This is clearly a rip-off of Aerodactyl. It just has a different color palette and face.
Second row, sixth column: Has some similarities to Snorlax, including lying down and having a large stomach.
Third row, third column: With its razor claws, this looks like some Denjuu -- closer to Hagumanoki than anything else. It also has some similarities to Scyther.
Third row, fourth column: This also looks like a Denjuu -- this time it looks like Scorpil with its arms out in front.
Third row, fifth column: Haha, I love the skull.
Fourth row, first column: Another one that looks similar to a Denjuu. Looks similar to Vanda, doesn't it?
Fourth row, fourth column: Cross between Magcargo and Muk, perhaps?
Fifth row, fourth column: Yes, this definitely looks like a Fungus. Except poorly drawn. The style of this, like many other sprites here, looks like the typical sprites in Red/Blue.
Fifth row, fifth column: Definitely looks like a Spinarak.
Sixth row, first column: Looks much like a Mewtwo.
Sixth row, second column: Looks like a poorly drawn Qwilfish. Or maybe it's just something original.
Sixth row, third column: Looks like a Ledyba to me. Except more rigid and made out of stone.
Sixth row, fifth column: Looks a bit like some enemy from Yoshi's Island.
Seventh row, second column: Clearly inspired from Totodile. Do I need to explain this?
Seventh row, fourth column: Looks like a mutated Geodude, especially with the face and arms. It's not exactly the same though.
Eighth row, second column: Yes this looks a lot like Gyarados from Gold. With a mutated face.
Eighth row, third column: This looks familiar to me, but I don't know why.
Eighth row, fourth column: Very much like Onix. With gravel on the ground.
Ninth row, third column: Very clearly inspired from Dragonite, but with a weird face and horn on top. And it's blue.
Eleventh row, eighth column: Has a few loose similarities to Charizard with its dragon-like body and wings.
Twelfth row, first column: Very similar to Moltres with few modifications.
Twelfth row, third column: Looks like the Denjuu Rhodanthe.
Twelfth row, sixth column: Looks somewhat like Cortos, especially with its bird-like body with flames coming out the back.
Twelfth row, seventh column: Looks like Mareep in Red/Blue style.
Thirteenth row, first column: OK, now I am
convinced that they were copying some Denjuu designs. This looks undoubtedly like Shellsterra. Just look at it. It has the cone-like shell on bottom,
with spikes protruding from it. Don't tell me that's a coincidence. OK, the head isn't the same, but still.
Fourteenth row, first column: Looks like a Pokémon again, but I can't figure out what this is supposed to be.
Fifteenth row, third column: With the wings, it looks a bit like Funmachine.
Well, I commented on more of these than I planned. But those sprites sure are interesting. I wonder why they copied some from Telefang and Pokémon. It's also funny that many of the original sprites are so poorly drawn that they remind me of the style of Pokémon Red/Blue.