trying to make a robotic tail but in need of dier help

[lorykrice]

I am new to robotics and want a moving tail but the only way i am going to get is if i make it myself. i have an idea written on notepad and have drawn out on how it would work but not so sure how i would actually make the tail wag and how to make the things turn on the inside of the machine using batteries and a wire going through it making it wag different speeds

[newInRobotics]

Would be useful to see the drawing

[waltr]

A gear motor with an eccentric arm.
  The tail motion would be same every time.
  By changing the motor speed you can change the tail wagging speed.

A servo controlled from an RC receiver/transmitter.
  The tail wags follow the joystick motion. To keep waging the tail keep moving the joystick back and forth.

A servo controlled from a Micro-controller (Audriuo, AVR, PIC, Axon, etc)
  Pre-programed motions can be selected.
  Lots of different tail wagging speeds, wag angles, etc can be done.