Continuity mistake: When Zarkov watches Kala's corpse, the amount of black goo changes between one frame and the immediate next one. This happens BEFORE her body starts collapsing.
Continuity mistake: When Klytus dies he is facing down; an instant cut later he is facing sideways.
Continuity mistake: After Klytus dies, the position of his right hand and arm changes drastically between shots.
Revealing mistake: When Ming dies, one can see his real left eyebrow. The makeup covering it is missing.
Continuity mistake: When Ming is about to die, he slips away from the spike, which has parts of it covered in green blood. When Flash sees him, the spike is fully covered in green blood.
Continuity mistake: The pilot hands Flash a People magazine to sign. When Flash sits down to autograph it, one can see it's already signed (seemingly from previous takes). Then he scribbles on the same spot again.
Answer: Spider.