A bird/dinosaur monster created by Finster,Hatchasaurus possessed a magical speaking computer heart called Cardiatron (he looks like a heart with the tentacles) that was able to re-assemble/enhance the monster after it was destroyed by the Rangers. First, the Tyrannosaurus finisher was used, which only temporarily defeated him. Then, the Megazord used its Power Sword to the same results. Hatchasaurus demonstrated incredible strength when he became his most advanced form the third time he was reassembled. Even though the Hatchasaurus initially didn't speak, Cardiatron spoke in an aristcratic, haughty intellectual manner. It wasn't until Red Ranger destroyed Cardiatron with the Power Sword and Dragon Dagger that he and the others were able to destroy Hatchasaurus once and for all with Ultrazord.
Hatchasaurus later reappeared in the second season when summoned by Terror Blossom. This time around it possessed the capability to speak with Cardiatron not speaking (strangely with Cardiatron's original voice and mannerisms). Like the first time, the Rangers had to destroy Cardiatron, before they could destroy the monster completely. To defeat it the first time, they merely emitted smoke from a nozzle in the Thunder Megazord's chest, but it quickly reassembled. The second time around, Hatchasaurus survives the Thunder Megazord Thunder Saber (which apparently destroyed Cardiatron inside of the Hatchasaurus), but is weakened enough to be taken out by the Tigerzord's thunderbolts.
Hatchasaurus was later seen in the Shadow World.The Fate of Lightspeed