It sure looks like a mini pokedoll, but there isn't much info available.
Then this auction shows up last week:
It contains the DX Munchlax Pokedoll, a cookie tin, and the mystery plush!
This time there is some great info from the seller:
"2005 Pokemon Center Yokohama limited stuffed large Gombe
I purchased in the Pokemon Center in Yokohama (2005) when the Pokemon Center Yokohama was opened.
Mascot of the image, was a bonus bucket of cans that is reflected together.
I will put up buckets and cans mascot."
With that to go on, some extensive googling later I was lead to this page of our fearless leader denkimouse
Specifically, this picture (the one on the right):
Its a mini Pikachu pokedoll, with a bead-style keychain and its from 2005 too!
It's my speculation that these two plush are related, possibly from the same promotion.
Since most mini pokedolls come in 3's, could there be a third? check out this photo:
The cookie tin shows 3 mascots, Munchlax, Pikachu and Treecko.
It would appear there might even be a mini treecko out there too (in addition this Treecko mini pokedoll).
If anyone has any info, sightings, etc, I would love to hear from you.
eevee_trainer's collection page has been updated with new pokedoll gets. If anyone wants to exchange links, just ask! :D