rat-tails is a form of:

Rat-tail



Same as: ratfish
ENGLISH MEANING
noun
1.
An excrescence growing from the pastern to the middle of the shank of a horse.
2.
The California chimaera.
3.
Any fish of the genus Macrurus.
adjective
1.
Like a rat's tail in form; as, a rat-tail file, which is round, slender, and tapering.