It's been confirmed DrinkyTengu is now doing the Coocoon. I'm not sure who was doing it in the beginning...but she's doing it now ^^ It's posted on her profile.
And I'm not so sure about Buki doing the Dander...here's what she posted in my Coocoon thread (
http://www.gaiaonline.com/forum/gaia-community-discussion/coocoon-artist-speculation-update-it-s-drinky/t.43384225_16/):
Buki
Whoa... what? o_oa
I remember speculations that said I was working on Gro-gain (which was kinda true. I did make the bottle sprite. Just the bottle.)
Then the Dander
Now the coocoon.
She said she did the Gro-gain bottle...but didn't say she did anything on the Dander...
Hope this helps!