"Hickory dickory dock,
The mouse ran up the clock.
The clock struck one,
The mouse ran down,
Hickory dickory dock"

This basic rocker unit can have many 'faces' - a little man - a sailing ship - a rocking horse - whatever you fancy.
The little mouse, however, has a special tail to tell!
All wood is 10mm square.
The rockers are a 63mm [2½"] diameter card disc cut in half.
The pieces of wood are 2x6cm and 2x 3cm. The shorter pieces create a simple counterweight, enough to balance the mouse. (Nuts or washers could be attached for models with a heavier 'superstructure'.)
The body is a rectangle of stiff card 6x5cm. sandwiched between the pieces of wood.
Build the head first - you could make him 2-sided - with 2 ears and 2 eyes. Inset shows main unit with one rocker removed

Now the clever bit!

Attach the tail in a vertical position. This will probably be insufficient to balance the head, but while the glue is still wet rotate the tail until a level model is achieved. It may be that the mouse balances with the tail at 'one o'clock' - perfect! (but if he's an hour or two late, who's bothered?)

The magic bit?
Stand the rocker on a rectangle of card - the slightest movement of the card, back and forth, will induce a rocking motion.