Updated.
Distinctive Appearance: A functioning manikin appears humanoid from the waist up but is all sheen below. Usually, the sheen chassis attached to the biological component is a simple two-or-three-footed walker. Sometimes the chassis of a small roller is used instead, and possibly even that of a ground-effect drifter. Mobility of the manikin depends upon the chassis. A walker chassis performs similarly to biological legs, while a roller chassis limits mobility in rough terrain but increases maximum speed on level surfaces; ground-effect drifters hover over the ground at a height of 1-10 feet and move over all terrain at a rate of 12.
Walker chassis leaves base land speed unchanged?
For the roller chassis, borrow this from maugs?
Rollers: Six great stone cylinders beneath a pyramid of rock, rollers replace the creature's legs and feet. Rollers add 20 feet to the grafted creature's land speed and give it the ability to trample foes, but the grafted creature takes a -8 penalty on Climb, Ride, and Swim skill checks. The grafted creature cannot run.
As a standard action during its turn each round, the grafted creature can move up to its speed and run over opponents at least one size category smaller than itself. This attack deals bludgeoning damage based on the grafted creature's size (see Table A2-3). A trampled opponent can attempt either an attack of opportunity at a -4 penalty or a Relfex save (DC 10 + 1/2 grafted creature's HD + grafted creature's Str modifier) for half damage. Prerequisites: Graft Flesh, baleful polymorph, expeditious retreat, creator must be a maug; Market Price: 10,000 gp.
For the ground-effect drifter chassis, I believe we did something similar for a semi-recent creature. I'll search for it.
Additionally, manikins must suppor their biological systems with food like any other organism, while their sheen chassis requires more specialized energy. In fact, without monthly recharging, the manikin trundles to a stop, unable to move. Returning to the cyst for a recharge like a shandard sheen is something a manikin should avoid, lest they desire early recall and deactivation. Manikins can fully recharge on a monthly basis with a shocking grasp or lightning bolt cast at the 5th level of ability and applied to a special capacitor inlet. Another method of recharge requires the manikin to stand idle four days out of 28, absorbing ambient sunlight on its sheen chassis. The sunlight is converted to charge, motive power, and electric life.
Modify the following, and add in a solar power component?
Electrically Charged (Ex): Walkers are powered by electricity. A walker normally carries enough charges to function for up to one month (30 charges). After this time, the walker becomes inert until recharged. Walkers generally return to their cysts before this time elapses.
Each time a walker uses its electrical discharge ability, it expends one charge.
Within a cyst, a walker may fully recharge after one hour of inactivity. Alternatively, a walker can recharge "in the field" if exposed to an attack that deals electricity damage. An attack that deals electricity damage restores 1 charge for every 5 points of damage the attack would otherwise deal. For example, a walker hit by a lightning bolt gains 3 charges if the attack would have dealt 15 points of damage. A walker gets no saving throw against attacks that deal electricity damage. Regardless of the amount of electricity damage directed at a walker, it cannot exceed its normal maximum of 30 charges.