Sharpie, food coloring, and acrylic paint. Easter egg.
These are Pisanki, or Polish easter eggs, - sometimes made from wood, but often actual eggs - hand painted.
easter egg faces
Ohoh Blog - diy and crafts: Babouchka Easter eggs...painting tutorial you could use to paint rocks!
Pisanki, kraszanki i drapanki...
Snowflake Pysanka Step-by-Step: Pencil