He protected his wharf warehouses with some automatons made from reinforced old crates and boxes -- the box golem.
Here's an artists take on a similar creature from io9
Box GolemNumber Appearing - 1d4
Attack - 2 fists (2d8) or 2 snapping claw-boxes (2d10)
Special - Surprises, Capture, "Mystery Boxes", Golem immunities, Vulnerable to fire, Immune to electricity
BD - d6 =  the box golem "opens a mystery box" to hinder its attackers. Typically, this one is designed to hamper or slow its attackers
MD - d6 =  the box golem "opens a final mystery box" to deal with its attackers. Typically, this one is extremely lethal
MV - 12
AC - 3
HD - 12 (60 HPs)
Save - 3
Mor - A
HC - Nil
CL/XP - 13/2300
Built from reinforced wooden crates and boxes, the box golem looks like an inanimate stack of storage containers until it is disturbed by intruders or thieves. It will surprise on a 1-3 on a d6.
When active, a box golem can be built to have nearly any shape. Most are humanoid in appearance with boxy fists that snap like claws. More "stylized" versions look like crabs, spiders and giant hounds.
Box golems attack by bashing with their wooden and steel reinforced box fists or some attack with snapping claw-like boxes with sharpened edges.
Box golems are often built with a number of "mystery boxes" contained within their structure -- poisonous snakes, scorpions, centipedes, caltrops, bear traps, explosive runes, poison gas, sleep gas, acid spray, etc.
If a box golem hits a target with both fists, it will attempt to catch and capture it within a box. The target must save or be trapped and locked within the body of the golem. The compartment is cramped and suffocating, but the victim will be safe until released. If the victim possesses exceptional STR or certain skills or magical abilities, escape might be possible at the discretion of the GM.
Box golems take half again as much damage from magical fire attacks. They are immune to electrical damage.