Nimrod the Scarlet Sentinel was a monster created by Lord Zedd from the Sentinel Statue in Angel Grove Park to finish off the Power Rangers while Zordon was MIA and Tommy was on his way back to Angel Grove. Nimrod appeared in "White Light Part 1 & 2". AC & DC were two warriors that were summoned by Nimrod when she battled the Thunder Megazord and then the new White Tigerzord. Tommy Oliver returned as the new White Ranger and finished off all three monsters with the new MegaTigerzord. Nimrod spoke but AC & DC did not and only appeared when Nimrod summoned them in giant form.
In part 1, Lord Zedd learned Tommy was returning to Angel Grove and attempted to turn him back into the evil Green Ranger and to keep the rangers occupied, he turns the Sentinel Statue into Nimrod. The statue was taking longer to become Nimrod and the rangers discovered Zedd's plan. Zedd was getting tired of waiting and created Nimrod who easily fought off the rangers. Zedd then made Nimrod grow to turn up the heat who also proved too much for the megazord. Nimrod then summoned AC & DC to finish off the megazord and greatly destroyed it, making the rangers retreat,
In part 2, Tommy returns as the new white ranger and takes on Nimrod himself with his new White Tigerzord and easily defeats Nimrod. Nimrod summons AC and DC again and they beat Tommy. Jason then arrives with his Red Dragon zord and helps fight off the three monsters. The other four Thunder zords appear and merges with the White Tigerzord to become the all powerful MegaTigerZord. Nimrod has AC & DC charge at the zord and the Tigerzord easily pushes them away. He then uses the Firebird missile blast which attacks all three. AC & DC vanish into thin air and Nimrod is finally destroyed.