A conniption fit is a spontaneous outburst of anger or frustration, usually precipitated by an act of stupidity or neglect. Wild animation, gesticulations, and flailing of limbs often accompanies said outburst, adding visual flavor to the experience.
"If your mother gets home before you clean this up, she'll have a conniption fit!"
Cats like to get a little loopy now and then, too. When their owner places catnip at their feet and they dose up, the behavior that ensues is a catniption fit.
I gave Casper a pinch of catnip, and he's going nuts...a regular catniption fit!