Creative to me is taking an animal (in most cases), modifying it to the point where it resembles the animal but is still individual.
Chimchar is a good example of this.
It is obvious that Chimchar is based off of some sort of primate yet it has features that make it not a primate. Note the tail of fire and body shape. Looking at Chimchar we can say, "Hey, that looks like a [insert name of primate here] but it's not, it's a monster."
Squirtle is not a good example of this.
It is obvious that Squirtle is based off of a turtle (LOL, I typed Squirtle here), yet it does not have features that make it not a turtle, if you get what I'm saying. It is just a turtle that has been modified slightly. There is nothing about Squirtle that I can think of that makes it different from a real life turtle.
Another thing that makes something creative is a less than obvious reason for the Pokemon having a certain name of feature. I really like the reason someone above me gave for Teddiursa having a crescent moon on its forehead. I had no idea and this just really impressed me. Another is Torterra. Once you think about it, it makes perfect sense. Tortoise+Terra. Torterra is obviously based off of a tortoise of sorts but has features that make it different to a tortoise (going back to my previous point). This is where the Tor comes from, but what about the Terra I hear you asking. Well IIRC Terra is the Greek/Roman name for the element earth. And since Torterra gains a ground type upon evolution then this is just great and it really impressed me when I put two and two together.
Another thing that makes a Poké(just worked out how to do that!)mon creative is its evolutions. What I see a creative evolution as is the designers not just slapping something on the first Pokemon and calling it a day. Note Rapidash: the designers just slapped a horn on Ponyta and called it a day, and don't try to argue with me, it's true and you know it.
Note Kabutops: The way I look at it the designers took their final copy of Kabuto and really thought about what to have it evolve into. There are numerous differences between Kabuto and Kabutops but they still look related. That to me is creative.
These are just my opinions so don't hate me for them, and you can't say I am bias to the 4th gen. I do actually like many 1st gen Pokemon, I just don't think they are creative.
Chimchar is a good example of this.
It is obvious that Chimchar is based off of some sort of primate yet it has features that make it not a primate. Note the tail of fire and body shape. Looking at Chimchar we can say, "Hey, that looks like a [insert name of primate here] but it's not, it's a monster."
Squirtle is not a good example of this.
It is obvious that Squirtle is based off of a turtle (LOL, I typed Squirtle here), yet it does not have features that make it not a turtle, if you get what I'm saying. It is just a turtle that has been modified slightly. There is nothing about Squirtle that I can think of that makes it different from a real life turtle.
Another thing that makes something creative is a less than obvious reason for the Pokemon having a certain name of feature. I really like the reason someone above me gave for Teddiursa having a crescent moon on its forehead. I had no idea and this just really impressed me. Another is Torterra. Once you think about it, it makes perfect sense. Tortoise+Terra. Torterra is obviously based off of a tortoise of sorts but has features that make it different to a tortoise (going back to my previous point). This is where the Tor comes from, but what about the Terra I hear you asking. Well IIRC Terra is the Greek/Roman name for the element earth. And since Torterra gains a ground type upon evolution then this is just great and it really impressed me when I put two and two together.
Another thing that makes a Poké(just worked out how to do that!)mon creative is its evolutions. What I see a creative evolution as is the designers not just slapping something on the first Pokemon and calling it a day. Note Rapidash: the designers just slapped a horn on Ponyta and called it a day, and don't try to argue with me, it's true and you know it.
Note Kabutops: The way I look at it the designers took their final copy of Kabuto and really thought about what to have it evolve into. There are numerous differences between Kabuto and Kabutops but they still look related. That to me is creative.
These are just my opinions so don't hate me for them, and you can't say I am bias to the 4th gen. I do actually like many 1st gen Pokemon, I just don't think they are creative.