Pool: [sys3.6.3.] 動く E.C.M.
Artist is Zankuro, his sys363 site is here: http://nekomimi.ws/~zankuro/sys363/
Product page is here: http://maniax.dlsite.com/work/=/product_id/RJ070638
This is a series of Flash anims, or "動く" (ugoku, "moving") with the title E.C.M. (Eroanimekatto's Collection). The girl seems to have the name or handle 'Eroanimekatto', kind of an abbreviation for Erotic Anime Catgirl. The animations are censored.
The Flash anims have been converted to animated GIFs in this pool. The original Flash has a few extra options, like changing the speed and choosing whether she's lactating or not.