From 300 blog

It seems as if in several instances, there have been characters who have provided some type of comic relief to counteract the drama of war. Who can forget 'Private Pyle' in 'Full Metal Jacket', 'Corporal Upham' in 'Saving Private Ryan, etc., etc., etc.? Frank Miller has continued the tradition in '300' where we are introduced to the Spartan warrior 'Stelios'.

While marching from Sparta to Thermopylae, the young Spartan hoplite stumbles while marching in formation. For this transgression, he is almost beaten to within an inch of his life by his captain before he is saved by King Leonidas who will be played by Gerry Butler. It seems that the price that this young warrior has to pay for his ineptitude is being referred to occasionally as 'Stumblios'. However, after his brief admonishment, he once again becomes an integral part of the famed Spartan phalanx. As part of his redemption, Stelios is called upon by Leonidas to deliver the first fatal blow to a Persian officer in the final battle. Since 'Braveheart' and 'Gladiator' were successful and had a few moments of levity, perhaps Zack Snyder will incorporate some humor into '300'.