You will need:

Yarn: whatever scraps you have lying around. Use a single color or make stripes. A stitch marker may be useful if using a single color, otherwise the color changes of stripes will indicate beginning of rounds.
Hook: 1-2 sizes smaller than recommended for yarn
Batting/filling
Tapestry needle to weave in end

Magic circle
Rnd 1: sc 6 st (6)
Rnd 2: inc in ea st (12)
Rnd 3: sc, incx6 (18)
Rnd 4: 2 sc, incx6 (24)
Rnds 5-10: sc in ea st
Rnd 11: 2 sc, decx6 (18)
Rnd 12: sc in ea st
Rnd 13: sc, decx6 (12)
Rnd 14: sc in ea st
Stuff egg with batting
Rnd 15: dec x6 (6)

Cut tail. Weave thread through outside loops of final round. Pull tight. Weave end through middle of egg. Roll egg through hands to evenly distribute batting.