Interlocked Snake Knot
I call this knot interlocked because each half turn of the knot is locked to the preceding half turn
In the photo the locked snake knot is on then left and the unlocked is on the right
Fold a cord in half and bring the upper strand in a half turn around the lower strand
Flip this upside down
Bring the new upper strand down under . . . .
. . . and up through the first bight. Pull tight If you repeat steps 1 - 3 you will get a unlocked snake knot
Take the upper strand and bring it down under and back up through the bight and pull tight
Flip the knot upside down and bring the upper strand down under and up through the bight
and again . flip knot, and bring upper strand around
and again
and again. Repeat until you reach desired length