This is a dynamically created mythical animal. He is writhing in front of us, his tongue is moving noisily. The maker's mark in the bottom is that of Chen Mingyuan who lived in the early Qing dynasty, flourishing in the Kangxi period (1661-1722). This piece is in the style of Chen but not his. A distinguished colleague wrote:
"The dog is very cute but almost certainly not by Mingyuan. His marks was widely used and abused during the Republican period to date and can be found on items of very good quality right through to complete tat. The dog though is nicely done but the finish underneath is just too poorly executed to be by the master. I have a couple of pieces with similar seals but almost certainly 20th century mine though I think mine are more on the tat end of the quality spectrum! There is an excellent publication on the works of Chen Mingyuan, the name of which escapes me for the moment, but even the authors are very caging about assigning authenticity to pieces. To be honest some of the work produced by the masters during the republican period were equal to or even superior to the original works. There are an increasing number of questions being asked of some of the very early pieces sold at the 70's Sotheby's Hong Kong sale upon which the K S Lo collection was founded with suspicions that many were actually dating to the republican period. Your other animalistic piece of Yixing may have a similar source though it too is still a very charming piece of yixing."