Willard claims that his own dad has left him forever and intends to steal a new one. Numbuh 1 attempts to get his father back by challenging Willard to a sousaphone playing competition, but is not very good.
In the end, Willard's father, who had simply left a few minutes ago to get milk, returns to him and Numbuh 1's dad is let go. Willard's dad, just like Numbuh 1, turns out to hate tuba music.
He was a competitor at the Toobathon Race in Operation: C.A.K.E.D.-F.O.U.R., and was seen in line at Vaseball Stadium in Operation: B.R.E.A.K.U.P.. He was last seen trying to fish out the Great White Asparagus in Operation: I.N.T.E.R.V.I.E.W.S., before being eaten by it.