Scalawag
/ˈskæləwæɡ/
Definition 1 of 2
Pro Tip 1/3Colloquial Usage
Used in casual conversations rather than formal speech or writing. 
When he hid my phone, I called him a scalawag.
Pro Tip 2/3Playful Connotation
Implies playful misbehavior, not serious wrongdoing. 
That scalawag always has a twinkle in his eye.
Pro Tip 3/3Endearing Term
Often used affectionately for someone who is mischievous. 
Come here, you little scalawag!