|“||No! You shattered my dre-e-eams!||„|
|~ Nightmare's final words before his death.|
|~ Nightmare's final words along with Professor Strickler & Game Face before his second defeat.|
Nightmare (voiced by Jacque Drew) is a sheep-themed outlaw, which enjoys both sleeping and inflicting nightmares on others.
Nightmare is first seen sleeping in a cell within the ship before Heckyl gently wakes him up. No longer asleep, he excuses himself and asks if he was snoring too loud, to which Heckyl answers he was, but his reason for awakening him is to aid him in his next plan against the Rangers.
His first target is Shelby, as she sleeps on a pillow Heckyl gives her to rest. Upon touching it, Nightmare enters her mind and causes her to perceive all around her as Vivix. She attacks her friends, which evade her moves, until she slashes the pillow in half, at the moment held by Tyler. He reveals himself before the heroes and makes his escape after taunting them. The day is excruciating for them, as they cannot rest while Kendall seeks the connection of the pillow to the outlaw, eventually figuring it out.
In response to the Rangers' strategy, Fury sends out real Vivix to tire them out even more. Though exhausted, they successfully defeat them, only for Ivan to attack them, suffering from sleepwalking. Koda tracks down the pillow and rips it in two, freeing the knight. After leaving Shelby at school, Riley is controlled by a pillow left on the helmet of his scooter by Curio. Meanwhile, Heckyl deals with the other weary Rangers until Shelby finds him out, her suspicions all but confirmed when Snide takes over and retreats from the battle.
Nightmare is then left by Fury and Curio to deal with the fatigued heroes, but fails as he is defeated both in normal size, by a combined attack of six of the Rangers, and as a giant by their three Megazords.
He was recreated by Wrench, along with Game Face. Both of them fought by the side of Professor Strickler. He gains a new outfit, one that this time resembles a baseball uniform, Nightmare used the Switch Eraser to switch the Red and Pink Rangers' bodies and later does the same thing with the Black and Blue Rangers.
After the Rangers get shock of getting each of their body's switch, the three monsters ambushed them, the Rangers try to fight back, but because their in new bodies, they get different weapons, resulting them get a beat down, the Green and Gold Rangers came in, but Nightmare was able to switch their bodies as well.
However the two Rangers were able to used their weapons just fine and takes out the three monsters, now over powered, Professor Strickler and the two monsters teleported away, the later returned in the mountain tops with the Rangers appearing, the Rangers montage, but it was a trick for Nightmare sneak up on the Rangers and switch the Green and Blue Rangers' bodies, and the Red and Gold Rangers' bodies, the three monsters were about to ambush them again, but the Rangers the Dino Steel to battle the monsters and gave each of the Rangers back their personal weapon to take on the monsters, but the Rangers were still out match, but right before they could finish them off.
However the Silver Ranger came into battle, but Nightmare manages to switch the Silver Ranger and Professor Strickler with the Switch Eraser, after a long duel the Pink Ranger (in the Gold Ranger's body) manages to make Nightmare drop the Switch Eraser, allowing the Red Ranger (in the Pink Ranger's body) to use the T-Rex Smash on the devices, switching the bodies back to the right person, with the Titano Saber Final Strike, Strickler was taken out, the Red Ranger then morphed into the T-Rex Super Charge Red Ranger, and with the T-Rex Super Charge Victory Maximum Strike, Nightmare and Game Face were taken out as well and later on after being enlarge by the Magna Beam, destroyed for good by the Dino Charge Ultrazord's Titano Cannon's Final Strike.
- Like with Somnibot and Rhinosnorus, Nightmare's puns, metaphors and jokes are based on sleep and bedtime (e.g. "You're all a real snore!" and "See you in your dreams!").