Page 163 - Geoffrey Budworth, Jason Dalton "The Little Book of Incredibly Useful Knots"

Cow hitch

A quick and easy way to attach any sort of cordage to a post or rail, this is a very insecure hitch,

unsuitable for heavy work (let alone tethering a cow), because the load falls upon only one leg of
the doubled bight with which it is formed.

Double the working end of the line to create a bight (1), and pass it around the intended
anchorage point (2). Then simply pull both long and short ends through the bight (3) and tighten

the knot (4).