Curly tail grub
A curly tail grub is a soft lure with a crescent-shaped tail on a thin neck. It is often called simply a grub; in Ukrainian the same shape is known generically as a twister.
How the tail is built
The tail is flat, curved like a crescent moon, and joins the body through a narrow neck. The flow presses on the concave side, the tail deflects and curls, the pressure on it drops — and the tail swings back. The cycle repeats continuously for as long as the lure keeps moving.
The thin neck here is not a weak point but part of the mechanism: it is exactly what lets the tail work with minimal effort.
Why it works on a slow retrieve
The slowest possible draw is enough to start the curl — even the free fall of the lure during a pause will do it. This is the main practical difference from a paddle tail lure, whose paddle needs a noticeable speed to work at all.
That is why a curly tail grub keeps working where the retrieve has to be slowed to a minimum: in cold water, when retrieving against the current, and on a hop-and-drop retrieve with long pauses.
How it is rigged
The hook goes in through the nose of the body and comes out along the centre line, without catching the neck. A damaged neck kills the action instantly — after that the tail just drags behind the body and does not work.
On a jig head the body has to sit straight along the shank of the hook: crooked rigging twists the line instead of producing action. To keep the body from sliding back on the cast, jig head shanks often have barbs or a wire keeper: a lure that has slipped down to the bend also stops working evenly.
Two tails instead of one
A twin-tail is the same shape with two crescents set symmetrically. Two surfaces give more resistance in the water: the lure sinks more slowly for the same rig weight and pushes back harder on the retrieve.
Because of that resistance it is more often fished on a heavier jig head than a single-tail grub of the same size — otherwise it simply does not reach the bottom.
A cut-off tail is already a different lure
A pike bites the tail off crosswise, and the lure loses not a centimetre of length but its entire action mechanism. A curly tail grub without its curl works like a plain soft body with no movement of its own, and there is usually no point continuing a hop-and-drop retrieve with it.
Where a curly tail grub is the wrong choice
Where a steady, strong rhythm is needed on a fast retrieve, the curl loses to the paddle: it works more softly and produces less vibration. And it does not help where the lure is not worked at all — on a stationary rig a curly tail grub does nothing. In strong current, on the other hand, the curl works continuously, and the lure creates more resistance than its weight would suggest.