Meet the Spiderbot V2: a 3D printed transforming Arduino robot that you can build to learn a few things about electronics and robots. You are going to need an Arduino Pro Mini, Adafruit 16-Channel 12-bit PWM/Servo Driver, Buetooth module, 12 servos, and a few other parts to complete the Spiderbot V2.
This 3D printed transforming robot is easily customizable if you know your 3D printing. The files for femur, tibia, and other parts are available here. As you can see in this video, the robot has multiple modes: