"Well, Cassidy, being evil has always come very natural to me..."
Donkeyvac was sent to Reefside by Mesogog to suck the youth from people and harness it into energy. After stealing the youth from countless citizens, Donkeyvac was faced by Tommy, Conner, and Ethan, and was more than a match for the three Rangers. After Tommy was distracted by Zeltrax, Donkeyvac overpowered Conner and Ethan until Kira arrived, plugging up the monster's nose with a pair of tennis balls, causing him to spark violently. Donkeyvac was subsequently blown apart by the Z-Rex Blaster, then resurrected and enlarged by the Hydro Regenerator. After a brief fight with the Thundersaurus MegaZord, Donkeyvac was destroyed again by the Ptera Rang and Dino Drill. After Donkeyvac's destruction, the youth was released and all the citizens were returned to normal.