Page 28 - September 21 2021 Important Japanese Art Christie's NYC

The sculpture is in the form of a mythical beast derived from an
ancient Indian sea creature said to have the body of a fish and the
head of a tiger, the literal meaning of its name “shachi” in Japanese.
Shachi were favored by Japanese samurai as symbols of defense
against fire, for the tiger-fish is associated with water. Pairs of shachi
were made as corner tiles or as crests on end tiles of temples, samurai
dwellings and castle gates throughout the Edo period. An alternate
reading of the creature as a dragon fish, with head, as here, of a
whiskered dragon, may have originated from a Chinese legend of a
carp that was transformed into a dragon after ascending a powerful
waterfall. Such connotations of striving against impossible odds
appealed to the samurai clientele for whom the Myochin school
of metalsmiths first made them as display pieces (okimono). The
overlapping plates of the fish body are related to the riveted plates
of Japanese armor that provide strong protection as well as mobility.

Myochin Shikibu worked in Edo, first under the name Shikibu and
later Osumi no kami. His dated works include helmets from 1689,
1704 and 1707.