Dic: ball of fire (balls of fire)

ball of fire (and fireball):

1. an energetic and ambitious person; a go-getter.

• That guy is a real ball of fire when it comes to sales.
• I don't want to hire some young fireball. I need wisdom and thoughtfulness.

2. A highly energetic or dynamic person. Also called fireball.

3. Informal. a very lively person

4. (1) a highly energetic and indefatigable person (2) someone whose career progresses rapidly

.... http://idioms.thefreedictionary.com/ball+of+fire ,

... http://www.thefreedictionary.com/ball+of+fire