The yellow one is made by acrylic yarn, the other two are made by sheep yarn. Those yarn all suggest for No. 6 knitting needle or crochet hooker. And, it's my habit to use NO. 3 knitting needle when I want to make a toy. :)
1. NO. 3 80cm circle knitting needle => for turkish cast on
2. NO. 3 DPN
3. NO. 2 or other small crochet hooker
4. toy eyes
6. sewing needle
Try to change its ear and mouth, then you could make a kitty or pig. Have fun!