As Lizard Man turns his head to run away from Trap Jaw, his hood becomes the same color green as his skin. The same thing happens a little while later when he says "Not this time, lady."
After kidnapping Celise, Trap Jaw is surprised to find He-Man and Battle Cat barring his way and suddenly has a visible tongue. In the wide shot that follows it, his mechanical jaw is green instead of magenta.
During the close-up of Adam piloting the Wind Raider at the start, his legging is flesh colored instead of purple, giving the appearance of a bare leg.
Orko's size keeps changing during the early scenes in Tahryn. He is very tiny when Adam reaches up Orko's shirt to grab the amulet, and oversized in the next show when Orko presents the amulet to Prime Minister Pangas.
When we first see Beast Man in the Snake Mountain throne room, Skeletor is sitting on his Bone Throne on the left, but the same throne is also visible in the background between Skeletor and Beast Man.
When Celice tests her powers on Skeletor's model of Grayskull, his bone-throne is visible in the background, but without the table in front of it. Both the throne and the background are incompletely drawn and only it's top half appears to be floating in mid-air.
When Man-At-Arms screams as he is is grabbed by a Giant Crawler, his voice is performed by Lou Scheimer instead of Alan Oppenheimer.