The Mind Control Squid was created by using the blueprints Brother Blood copied from Cyborg's schematics during the episode Deception. Brother Blood unleashed it upon the Teen Titans after Aqualad lead the Titans towards Brother Blood's underwater H.I.V.E. Academy. The squid attacked the Titans without warning, severely damaging the T-Ship and forcing the Titans to separate.
The squid proceeded to attack Aqualad and Beast Boy, both of whom were actually searching for it. Beast Boy and Aqualad fought it valiantly, and in the end the duo managed to defeat it.