The fox is a bit failure, because looking at the real logo the fox is way more "round". And the earth could be a bit more clear with the continents. Otherwise a pretty good "copy".
i don't won't it to be exacly like the real firefox logo, i maked my own version for the FF logo :]
Looking at the actual firefox logo, the snout makes it more recognisable as a fox. Also the space between the ears. Also the arm is bent. So these are some things you could maybe change about yours to make it more like a fox. Nice colors you chose.
add more detailes to the tail