MOA was a half bird, half fish “god” worshipped by the Shargoans on planet Tokl. Alien visitors were usually slaughtered as a sacrifice, but if they wished to challenge MOA the stone chest would open to reveal a timer and a question, “Zikzbuzizizib?” which is early Alpha Centaurian for “What is the strongest of all things?” The answer is love and not, as nearly everyone previously had thought, titanium.
No one could answer this until the Doctor and his friend “Ixionian” did, which activated a self destruct so that MOA and several crushed Shargoans were no more. This caused the Shargoans to gradually halt their bloody ways. None of them realized that MOA stands for Monitor, Observe, and Advise, because the statue had contained a camera in its eyes that went direct to Lord Darval and a computer brain which analyzed the situations for him.