Snarling iron

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".

[1] Examples have come to light in different historical contexts, as in Chanhudaro,[2] Indus valley civilization.

Snarling iron excavated from Chanhudaro, Purana Qila Fort, Delhi