Milk Boy (ミルクボーイ Miruku Bōi) is one of Cappuccino's former employees.
Milk Boy is a huge man, his size making the already short Cappuccino seem like a mere halfling with the man barely reaching above Milk Boy's waist and his girth being equal to one of Milk Boy's legs. His fist is as large as Gildarts Clive. He has an unevenly-proportioned body; his huge torso easily outsizes his stumpy legs and his long hands reach upto his knees, his stance when upright giving the impression of a gorilla. His face is akin to that of a healthy baby's, with an entirely bald head but for a small narrow fringe curling up his forehead.
Milk Boy's outfit resembles that of a normal Cappuccino's Bar waiter. He wears a full-sleeved shirt, complete with barrel cuffs. Over this is a dark waistcoat with three buttons. His attire is completed with a pair of dark formal trousers and a simple apron which reaches upto his knees tied around his waist. As if to emphasize his similarity to a baby, the man has a bib with a polka dot pattern tied around his neck and a pacifier in his mouth. He also has rouge applied to his cheeks, making a dark circle appear on each.
Not much is known about Milk Boy's personality except for the fact that he is prone to make childish utterances such as "Goo goo gaa gaa", which is in keeping with his infantile appearance.
When Gildarts escaped with two of his slaves, Cappuccino called for Milk Boy to pursue the Mage. Milk Boy took a drink from his milk bottle and immediately powered up. He took off after Gildarts on all fours, with Cappuccino sitting on his back.
But the duo did not give up, approaching their targets aboard their own boat when they were helpless due to Unicol's attack. On Cappuccino's orders, Milk Boy immediately engaged Gildarts. He wasn't able to land even one hit on the Mage, but managed to annoy him enough for him to stop holding back and belt Milk Boy right into Unicol's mouth.
A completely unharmed Milk Boy was spat out by the monster upon its defeat later. He was captured by Gildarts and tied up in the very boat he arrived in, finally ending the chase and allowing the group to continue their journey West.
Super Hi-Hi (超Ｈｉ－Ｈｉ, Chō Hai Hai): After taking a swig of the liquid in his milk bottle, Milk Boy appears to gain an energy boost, allowing him to get on all fours and run at great speeds like a gorilla, even if he has a heavy object on his back.
- Enhanced Speed: Milk Boy's speed is enough for him to catch up to an individual as fast as Gildarts Clive. But his reflexes do not seem to sharpen to accomodate this increase in speed as he was easily tricked by a young Gray Fullbuster to run into a wall of ice.
Enhanced Strength: Milk Boy can easily carry a person of Cappuccino's size on his back while running, showing no signs of fatigue. One punch of his enough to cause a large iceberg to rock precariously,, although not enough to even faze Gildarts.
Milk Bottle: Milk Boy possesses a normal milk bottle, but the liquid inside seems to act like a literal energy drink, allowing Milk Boy to run at speeds which outmatch even Gildarts Clive and carry a man like Cappuccino on his back at the same time, although the drink does not seem to sharpen his reflexes correspondingly as he ran full speed into a wall of ice created by Gray Fullbuster because he didn't notice it.