Thanks for that.  I kinda get how it could be done with game construction (I'm not actually putting these into a game ATM though, maybe later) but I was thinking about GIF animation.  I guess the method you described of them flying outside the edges of the graphic rather than showing the full trajectory would be the way to go. 

I'm surprised no one has commented on this yet.

Anyway, the answer to your question is particle effects, my boy!
All you need to do is animate the ice cracking, then switch this sprite with a sprite of the caveman in a "breaking out" pose, and have the game generate a bunch of "chunk of broken ice" sprites around the new one, making it look like he smashed out and saving you a lot of headache. It might sound kind of weird at first, but lots and lots of games use it as a timesaver and a practical visual effect.

Take the Castlevania games, for example. Whenever you break a lamp or candle for cash or a subweapon or whatever, it looks like whatever you whipped got smashed into a bunch of smaller pieces. But what's really happening is, upon the candle recieving damage, the game removes the sprite from the screen and generates a bunch of sprites that look like broken chunks of the original one in its place! This way, they can make it seem like it broke without having to animate a buttload of additional frames. It actually has significant advantages over hand-animating a break, in that while an animation will always be the same, the "chunk" particles can spawn in different places, making it seem like a different effect each time.

You could probably adapt this to a traditional animation too, if you just switched from cracked frame to caveman frame and added a bunch of ice chunks in that fell out of view afterwards. It'd have pretty much the same effect while, again, saving you a ton of trouble.

Hopefully this explanation isn't too obfuscated and you can make out what I'm trying to say, I'm not very good at explaining things. Your NES-style sprites are some of my favorites sprites on the site, and it would suck if you got stuck on something that could be solved easily enough with the right workaround. I hope this helps you avoid 500 frames of spinning ice-chunks.