Working on this as a portfolio piece geared toward one of the places I'd like to get an internship with. The concept art is from Arenanet, their Guildwars 2 concept art book. I've had a lot of fun with the facial expression, but sadly strayed quite a bit from the concept now so I might have to save this version for myself…
Your proportions seem way off. The shoulders on the concept looks very wide and give the toad a 'warrior' feel. Yours seems to not have this look and almost looks like dwarftoadhuman. I think the head is also a little too large.
Thats such a sweet concept, this should look good! :) From a quick 'frog' google image search, I think the shoulders look fine - it seems frog arms don't join quite as smoothly to the back as humans do. But you might want to flesh it out a bit more if better fit the armour joins, as the flesh won't be seen much around…