Penny Crayon.

Artful Penny could indeed draw anything she wanted with her magic crayon and it would spring into life. A fantastically useful toy to have. Only her best friend friend Dennis knew her secret so the two had acres of fun winding up adults, nosey-parkers, bullies, bad guys, teachers and ne'er-do-wells with her creations, or solving problems for folk, or sketching their way out of tricky situations. Penny would scribble away, her arm becoming a blurr as she worked and then - hey presto! - her line drawing would leap off the drawing surface as a fully-formed 3D object.