Private Willy is one of Milo's minions, The Patapons. He's a runt of the minions and was one of the only Patapon who was not brainwashed by Fawful. He praises for Milo's friendship, he even gives Milo the power to inhale enemies.

An obnoxious little kid voice could work for this little rascal. But any voice you believe would fit the character, go on ahead and try it.