You can use a different size hook to make it smaller/larger. I recommend using the same brand of yarn for each color.

Materials needed:

• 4.0 mm hook
• red yarn
• white yarn
• black yarn

Pokeball coaster front:

1. (white) MR, ch 2, dc x12 into magic ring, (black) sl st (12)
2. (black) sc in BLO around, sl st (12)
3. Sc, inc in FLO around, (red) sl st (18)
4. Ch 1, (black) ch1, dc inc, (white) dc, dc inc x4, (black) dc inc, (red) dc, dc inc x4 sl st (28)
5. (red) ch 1, (black) ch 1, dc in same st, dc in next st, (white) dc, dc inc x6, (black) dc x 2, (red) dc, dc incx6, sl st (40)
6. Ch 1, (black) ch 1, dc x 2, (white) dc x2, dc inc x6, (black) dc x2, (red) dc x2, dc incx5, dc x2, sl st (52)
7. (black) sc around (52). You can leave a long tail to clean up the pokeball lines if you want. Same goes for the red and white. Trim and fasten off the yarn on the back side as needed.

Coaster back:
(black) Repeat rows 1-7, omitting row 2. Leave a very long tail to sl st around.

Connect the two pieces:
String the tail through one of the stitches of the pokeball. Sl st around the edges to close (52)
Optional: If there is some yarn left over, you can also connect the black part of row 3 to the back side.