Every time poor Barney & Fred needed his help the little fucker was sleeping. Even when he helped them he’d bitch about being woken up.
I realize it was the 60’s, but how much pot was this prick smoking?
Well, you have to figure in jet-lag all the way from the planet Zetox.
And shit. Fred and Barney were dum-dums for not realizing that.
Ever hear of jet lag? He traveled from another planet to Earthstone and then he also traveled back through time as well.
I know people that fall asleep on the subway on their daily commute
He was a carnivore and spent most of his days napping between meals. Once he gets hungry, it’s barneyburger time!
I just assumed that existence on this work was so very tedious and boring that he spent most of his time napping.
I imagine if I had his powers, I’d be doing some pretty tiring activities in between talking to Fred and Barney as well.
That would be an excuse on the first episode he appeared on.
But he was asleep during every episode.
Makes sense when you think it through. Here’s a picture of the Great Gazoo.
Assuming his skull is the size it is to accomodate his head, he needs to pump a great amount of blood into his brain, especially during waking, beta wave activity.
Although artist Michale Paulus has not yet included The Great Gazoo in his series of cartoon character skeletons, it’s no stretch of the imagination to see what the Great Gazoo’s heart is up against, given the ratio of chest cavity to skull.
I always assumed he was just lazy, not tired.
Do you know how long it takes to get over jet lag if you travel from say, San Fran to China? It can take days. He traveled much farther and when back in time too. It’ll take years for him to adjust
What if he was traveling primarily North (or South) and not across time zones? 
I always thought it was the sheer lack of intellectual stimulation.
Yeah, I thought he was just bored studying the “dum-dums.”
I think he had Mono.
This was my thought as well. Carrying around that huge melon on top of that tiny body had to be tiring.