You can crochet such Acorn using this pattern

Size of ready toy is about 6 cm/2,5 in.(without tail)
Size of the toys depended from yarn thickness, hook thickness or solidity of crocheting.

Materials
• Yarn YarnArt 50g/160 m, 55% cotton/45% polyacrylic - colours A and B.
• Crotchet 1.75 mm
• Fiberfill
• Needle
• Keychain ring (if you want)