Luffy amigurumi is about 9 cm (3.5 inches) tall.
I used small ply balinese cotton yarn (8 ply sport yarn) and Tulip hook no. 2/0 (2 mm hook).

Used stitches:
MR = magic ring
ch = chain
sc = single crochet
hdc = half double crochet
dc = double crochet
inc = single crochet increase (2 sc in next st)
dec = single crochet decrease (join next 2 sts into 1)
sl st = slip stitch

The free pattern can be found HERE.
The printable PDF is a total of 5 pages.
This pattern is available in English and Indonesian.