The Cat from the pictures is made using Himalaya Dolphin Baby yarn (more than 1.5 skeins of the main colour) and a 4.0mm size hook, and YarnArt Jeans with hook 2.2mm for details like the eyes, whiskers. My plushie, made with these materials is about 30cm (12 inches) high. Of course you can use any yarn you like.

The pattern is meant for beginners and intermediate crocheters.