For sure you'll need mechanical skills - robotics require to make clever mechanical designs. And of course you'll need programming skills and knowledge in electronics. As more skills in these areas - than better.
When it comes to work as animator things become even more complex - you'll need some artistic gifts in order to make the movements natural. Animator is working in the area between the art and the electronic.
I would not say "hard" or "easy" - everything depends on do you like this or not. If you like the robotics and the animation, if you have passion for this you could learn the things and soon you'll become really good in this area.
Currently there are many platforms (like Arduino) and ready to use components (like hobby servo motors) which dramatically simplify the design of robots for animation. Of course for more professional projects you'll need to make your own designs. Personally I'm always excited when I have to make something that moves and reacts