Cheng: He certainly is one Celt with a lot of personality!!!!
I vote for keeping the tattoo because it makes him look so weird and individualistic, which is hard to achieve with these little folks!
Have no earthly idea if Celts had tattoos....I think it was too cold for them to run around with their tops off, and when the sun did finally shine for more than 30 seconds, they would blister being so fair skinned.
And with the seriously high death rates from infections and no antibiotics back then, it seems like he would not have a tattoo for long...because he would be dead. And the state of injection needles seems nonexistent then.
Ka-ching, ka-ching....my two cents worth....from a Celt many generations ago, Pgal 
Actually, though it would have been bitter cold in the winter months,
during the summer months it would be perfectly feasible.
Even during the winter, it they had built up a tolerance to the cold they could have at least gone to battle with no tunic.
Actually, there were some Celts who would go to battle nude.
Though they did have the technology to make tunics.
And according to the Wikipedia article on Celts, it says that they did wear tunics.
As for tattoos, I know they had them. And they were common.
Pgal, you may be surprised on what people back then knew of medicine and infections.
Though it is nothing like our king of modern science,
if they do something that kills them a few times they will quickly find a way around it.
