Spider robot is a bit complicated in terms of moving parts, unlike other robots it has more than 4 moving supports, that is, legs.
The main building material is soldered paper clips. It makes no sense to explain how the leg movement mechanism works; you need to carefully watch the video clip and understand the principle of work.
The robot drives a mini motor, similar to the motor in a cell phone that creates vibration. The worm gear mechanism creates a reciprocating motion, bringing the entire mechanism into motion.