ThegreenVerdiesarethetiny,butbraveguardiansofthelakeside.TheyoungVerdiesonlybecomeguardianswhentheirhairturnsbrown.Untilthen,however,lifeisboring.Theyoungsterswithgreenhairarenotallowedtoflyonwarblers,notallowedtorowalone,andthey'renotallowedtoridewildfrogsattherodeo.WillyWhistle'sbigdreamistobecomeaguardian,buthiscuriosityalwaysgetshimintotrouble.However,thewholelakebecomesatriskwhentheenemiesofthelakeside,theGrimpsandtheswans,enterintoalliance.Theguardiansarehelpless,butWillycomesupwithadaringplaninordertosavehishomeandhistrappedfriend,JeremiahJump.Luckilyheisnotalone,becauseGrandpa,thewatersnakesandthefrogsalsocometohisaid.