These make no sense. Why would Magcargo turn into Gigalith? Actually it would make more sense for Magcargo to turn into a lava turtle, as it's another slow animal with a shell, plus it wouldn't just get bigger.
Magikarp and Gyarados are based on wind socks and on the legend of the fish who became a dragon but got its dragon powers removed because it was being a douche to everyone, so it makes sense. Not sure about Dragonair turning into Dragonite, though.
I don't know what you were thinking with the Torkoal one. All fire quadrupeds, but they have different concepts.
Venonat and Caterpie last stages switched make sense, but Butterfree looks less poisonous than Venomoth.
Now, you know what a cool evo line would be? Remoraid to Octillery to Mantine. Three different animals from the sea based on artillery: Remora gun, octopus tank and manta fighter plane. It also makes sense because Remoraid sticks under Mantine's wings, like a plane with two guns.
