I have just finished making two little monsters for my little monster for his upcoming birthday.
They are both made from the same crochet pattern by Alison Hoffman of Craft is Cool (which is available for free here on the Bernat blog). The different sizes have been achieved through different yarn weights and hook sizes.
I used two strands of acrylic DK in Fushcia and a 4.00mm crochet hook for the tiny guy, and Cygnet seriously chunky in Meadow Green with an 8.00mm hook for the lager guy.
I have backstitched the felt eyes in place rather than using fabric glue (like the pattern suggests) so that they hold better.
These were so quick and easy, and actually quite enjoyable to make. I think I'd like to make one a little bigger to complete the family, but I'll have to see what time I have!