This pattern is available in the book: Harry Potter Knitting Magic: More Patterns from Hogwarts and Beyond by Tanis Gray (Photos by Insight Editions, Publisher)
An interesting creature calls for interesting construction. Begun at the neckline and worked downward through the body, live stitches are placed on hold for various body parts, omitting the need for excessive finishing, then put back on needles and worked later.
Stitches are then picked up along the original cast-on for the head. Wrap-and-turn short rows are used to shape the heels and elbows, while I-cords create his grabby fingers and toes. His bill is grafted together using Kitchener stitch for a seamless join.
Better hide your treasure!