Hi!
This pattern is very easy to crochet.
You could use cotton or plushie. The pattern has steps specific to crochet with plush yarns.

Materials what I used:

COTTON:
YarnArt Jeans №18 (pink)
YarnArt Jeans №75 (blue) (on instruction photos)
Size A/2mm hook
6mm safety eyes

PLUSHIE:
HiMALAYA Dolphin Baby №80363
Size H/5mm hook
12mm safety eyes

Black yarn for smile and brows
Scissors
Yarn needle

I hope you enjoy crocheting this amigurumi <3