Baroness Emmuska Orczy 
Skin o’ My Tooth [EPUB ebook] 

Skin o’ My Tooth, aka Patrick Mulligan, was created by Baroness Emmuska Orczy, and appeared in several stories which were collected in Skin o’ My Tooth.
Mulligan is an ugly, portly, but particularly sharp Irish lawyer who goes to great lengths (even unscrupulous ones) to get his clients off. Usually this involves him solving the crimes himself. The nickname comes from one client who described Mulligan freeing him “by the skin o’ my tooth.”