i agree most "monster fish" but i think we can all agree that rays shouldnt be sold to beginners
x2 anything with big teeth or stingers, or venom just like with any other animal isn't even imo beginner friendly. You do an opps in handleing those fish and people can get seriousely hurt. most people don't keep monster fish because of space requirments and initial investment... not because they are "hard to keep". The bigger the animal the easier it is to get hurt, give that animal big teeth,spines, ect and even something docile become dangerous. ime rays can be dangerous anytime.. not just when trying to catch, anytime i have to mess in their tank you must always be aware of where they are, and be wary. Can they make great pets? sure. but its the difference between owning a domestic animal vs a wild. different set of rules.
Oscars imo are the original gateway monster fish.