Grumble Bee was created by Finster for Rita Repulsa, sent to mock Billy after receiving his first "B" on a test. Attacking Billy and Trini, Grumble Bee put up quite a fight, flattening the two Rangers with his powerful sonic attacks. Alpha created a device for Billy to use against Grumble Bee, blowing some kind of foam on the monster, disrupting his sonic attacks. When the other Rangers arrived, Rita made Grumble Bee grow, but he was destroyed by the MegaZord's Power Sword. Later on, when the Trumpet Top monster created hallucinations of previous monsters to wear the Rangers down, he began with Grumble Bee, who surprised the Rangers near the beach. Grumble Bee was later resurrected by Finster to guard the Power Rangers in the Specter Theater. Grumble Bee later attended Rita and Lord Zedd's wedding, bringing some type of large flower as a wedding gift. He was later amongst the army monsters to grow and battle the Thunder Zords, where he was destroyed by the White TigerZord's Thunderbolt.