First Stage (Base Pokemon):
Birdley
Type: Dragon
Ability: Intimidate
Combative Pokemon
Can be found in the wild at level 5.
Pokedex Entry:
"Self-Centered and Ruthless, Birdleys will attack any creature in sight, even their own species, in order to survive and evolve"
At level 30, Birdley evolves into Creatureley:
Type: Dark/Dragon (or maybe Poison/Dragon)
Possible Abilities: Rough Skin; Tough Claws
Opportunist Pokemon
Pokedex Entry:
"Birdley's evolved form, they lurk in the shadows of caves and forests, waiting quietly for the right moment to swiftly strike and eat their prey."
At level 48, Creatureley evolves into Ridley:
Type: Dark/Dragon
Possible Abilities: Tough Claws; Regenerator; Intimidate
Sinister Pokemon
Pokedex Entry:
"A Creatureley that has managed to fully evolve, Ridley stalks the night sky, fearlessly diving down onto his prey and any opponent in sight for food, stories of Ridley's brutality are often told to unruly children as a means to scare them away from doing bad things in fear that Ridley will come and take them away while they are sleeping."
I would personally prefer normal Ridley be the final evolved form for the sake of continuity with the later forms, but I guess it would make more sense for the normal evolution changes to be similar in design and for the item and mega evolutions to have more drastic changes.
When traded while holding a metal coat Ridley evolves into Meta Ridley:
Type: Steel/Dragon
Possible Abilities: Levitate, Defiant, Speed Boost (Hidden)
Wyvern Cyborg Pokemon
Pokedex Entry:
"It's body is infused with all kinds of high-tech weaponry, it is a hunting and fighting machine feared by all."
And finally, Meta Ridley can Mega Evolve into Omega Ridley:
Type: Steel/Dragon
Tentative Abilities (Couldn't decide completely, but Megas only have the one): Speed Boost, Mold Breaker, No Guard, Levitate.
Phazon Wyvern Pokemon
No individual Pokedex Entry