In the film adaptation, he was portrayed by the late Scott Plank, whose memory the film was dedicated in.
Trout Walker, whose father owned the town's lake, tried to win the love of Katherine Barlow, the beautiful school matron, but she fell in love with Sam, a black townsman. Trout led the charge behind an angry town mob and killed both Sam and his beloved donkey, Mary Lou. The unjust murder of her lover turned Katherine into Kissin' Kate Barlow, a notorious outlaw. After he murdered Sam and Mary Lou, the town's lake dried up and the Walker family lost all their money.
Years later, Trout and his wife Linda tracked down Kissin' Kate Barlow and demanded to know where she buried her treasure at gunpoint. Rather than tell Trout, Barlow made the choice to commit suicide by the lethal bite of a yellow-spotted lizard, so he could waste his years searching.
Trout, his children, and even his grandchildren have spent their lives digging for the treasure, and he passed on his obsession to his granddaughter, Warden Walker. After his death, she built Camp Green Lake for delinquent boys, to speed up the process. However, Stanley Yelnats IV found the treasure, causing Trout to die in vain. Kate Barlow got the last laugh, and the Walkers were finally brought to justice (as if by divine providence, it began to rain at Camp Green Lake almost immediately after the warden was arrested).
*Trout Walker serves as the Bigger Bad of the film because his actions led to the events of the film.