Froakie was revealed to be 0.3 metres, and was smaller than my thoughts. He's tied with Eevee for being the smallest starter Pokémon.
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I have claimed: Staraptor (01/12/13), Shiny Stone (02/12/13), and Limber (02/12/13).
Come to think of it, Rattata seams so vary in size so much that I feel disjointed trying to remember what size it is.
First playing the game, I felt that rattata was the same size (if not bigger then) Pikachu,
especially after seeing Raticate, which also seamed to be much bigger in the anime then the games alluded to.
Rattata is shown in one Episode in the Arms of a Small Child and yet looked small enough to be held in the palm of her hand if she had the mind to.
In another episode, it's shown to be quite large, much larger then a only a foot long. Maybe they don't measure it's tail?
Salamence is what comes to mind for me. I was expecting this massively huge, 8-9 feet tall dragon...
...and come to find out, it's only two inches taller than me. (I'm 4'9", it's 4'11") Cue me going "Really? Wtf."
In fact, Keldeo also comes to mind. I had a feeling it was smaller than the other members of the trio, but not 4'8" small.
Claims: Oshawott, Ice Body, Magmarizer, Griseous Orb (July 1, 2012) Cross Poison (September 26, 2012)
Pokemon X Progress
Reset -- you can watch the progress here
Fennekindle ==> RainbowSylveon
JWittz has done a video on this (well some Pokemon). And I put the blame on Game Freak for being terrible estimators of weight and height. And with that, I tend to ignore a lot of what the Pokedex says about weight and height.
And when you think about some the rideable Pokemon they show in the Anime (e.g. Charizard, Salamance) and actually look at Game Freak's pathetic excuse of height, you can barely ride on them.
Golduck. Seriously, Golduck is huge compared to some other Pokemon. I won't bother listing examples, I'll let people discover for themselves just which Pokemon Golduck is bigger than. I always thought Golduck was about 4 foot in height, turns out it's much bigger than that.
Garbodor at 6'03" and Beartic at 8'06" also surprised me, since I've always thought of them as smaller than that too.
Thunderbolts and Lightningrods!
My XY trade shop: offering IV breeding leftovers, special Pokeball females and egg move parents!
Joltik. I wasn't expecting it to be that tiny.
Smeargle is 3'11", according to the pokedex, which would make him roughly the size of a seven-year-old child...much bigger than the beagle-sized creature I initially had in mind. Maybe that includes the length of the tail, because the smeargles we saw in the anime seemed to be quite a bit smaller than that. The illustration in the DPP dex seemed to think otherwise, however.
They're always bigger or smaller than what I thought...
But FURRET... 5'11"?
(I couldn't think of a good username so I used my fav pokemon)
I can't believe no one mentioned the Anime version of Slaking, it went from being King Kong in my mind, to a small gorilla. Also, most legendary Pokemon, with a few exceptions, were smaller than I envisioned them being, especially the ones that embodied aspects of nature, or time and space.