The Missing Bone

S12 E17: With Dr. Oliver "on sick leave" (due to his demorphing troubles), Dr. Anton Mercer, Trent's adoptive father and alter ego of Mesogog, is brought in by Principal Randall as the substitute science teacher. He immediately stages a field trip to the Reefside Museum, which leads to Kira ending up in a storage room where she is forced to submit to the will of a hypnotic dinosaur skull. The creature gives her a sour attitude towards her friends, and ultimately leads her to Tommy's lab to steal a bone she had recently noticed while helping him take inventory. The bone is revealed to be the final component of Fossilador, a hypnotic dinosaur monster created by Tommy and Mercer years ago! Can our heroes stop her before she restores the bony creature?