You are the best evaluator of your work and you have to decide as to which of your work should be included in your portfolio. Last but not the least; your work should demonstrate your talent. If you carry original work, it definitely gives you an upper hand.One should avoid compiling copies of most popular cartoon characters as nobody wants to see how well you can draw 'Tarzan' or 'Alaadin'. Prospective recruiters are rather interested in assessing how well you can draw something from your own creativity and imagination. This gives you an upper edge. It is better not to include any piece of your work in your portfolio, drawn on the basis of someone's suggestion else it will be difficult for you to explain the character properly.

If you are good in drawing animal characters', don't stop at that, you should be able to draw human characters as well. People with multiple skills are preferred by employers since they do not like to hire different people for creating different type of characters. Therefore, your portfolio should consist of a good variety of your work.Last but not the least, your personality makes a lot of difference. You can distinct yourself from the crowd by the way you present yourself, your body language, your mannerism, the way you speak, listen and walk. But most important of your personality trait in the eyes of an employer is your intelligence, your creativity and your grasping ability.