You can also use bones/shapekeys to make him non-mirrored if you wish.
The topology so far can be improved, too. Generally, it's best to make the topology consistent for higher poly models (it's very inconsistent with the tail right now, some of the segments go form really thin to wide) Use the sculpt smooth tool a bit here and there to make it a bit smoother and consistent. If that doesn't work, topology editing and edge loops can work.
The topology so far can be improved, too. Generally, it's best to make the topology consistent for higher poly models (it's very inconsistent with the tail right now, some of the segments go form really thin to wide) Use the sculpt smooth tool a bit here and there to make it a bit smoother and consistent. If that doesn't work, topology editing and edge loops can work.