The Collaborative International Dictionary
Snarling \Snarl"ing\, a. & n. from Snarl, v.
Snarling iron, a tool with a long beak, used in the process of snarling. When one end is held in a vise, and the shank is struck with a hammer, the repercussion of the other end, or beak, within the article worked upon gives the requisite blow for producing raised work. See 1st Snarl.
Wiktionary
n. A tool with a long beak, used in the process of snarling, or forming raised work.
Wikipedia
A Snarling iron is a metal worker's tool used to drive the walls of metal vessels. "A snarler... is a worker in teapots, and may... be compared with the leaf bumper who bumps up the leaves commonly seen in metalwork". Examples have come to light in different historical contexts, as in Chanhudaro, Indus valley civilization.