this looks 10000 times better than the frog you posted, this actually looks quite good
all i can say really is keep working at it!
**edit, ok after looking at it a bit more, im going to say this, avoid making things too round, specifically his bowtie thing? it just looks like string now, and if it is string its far too thick....also with hair try to give it some more character(could just be the picture) but it looks like its just thick chunky strands that dont really seem to flow or go anywhere
hair requires massive depth to look great if you want a realistic look, if you want more of a cartoony effect then i think youve done a pretty good job, it just needs to be a bit cleaner(the seperation, and th e strands)
so ill just comment a bit on doing realistic hair, in order to make hair lok realistic as ive said it needs depth, what this means is that hair isnt flat, and hair doesnt always flow straight...there are bends waves, etc
http://www.deviantart.com/deviation/29250128/
this is a drawing i did, and you can see all the spots the hair dips and waves...how this should help you is by looking at how i used lines to show certain movements and such...this should also help when it comes around to painting
well hopefully it helped ateast!
Starks