Timeline.

At (1) its a shot of just the spiky ball in the sky so you know its falling from the sky. the next frame (2) you know its fallen from the sky onto the flubber and you can see the reaction it is getting from being hit by a spiky ball. not sure if you can see this in (3) but the spiky ball is twisting and trying to get out of the flubber to escape because it knows its in trouble. Frame (4) it is going for the kill and is reacting by morphing upwards to absorb/eat the spiky ball. In (5) the spiky ball is fully covered and is trying to escape by extending its spikes to break through the fubber. At (6) is the spiky balls last attempted to escape giving it all its got but as you see in (7) it was no successful and is going back to its original form. Then at (8) you see that it is now starting to eat/absorb the ball and you start to see some changes happening to the flubber and that it is actually starting to change into the rusty metal of the spiky ball. in (9) you see the conclusion and result where it has gone back to its normal form with the exception that from absorbing the spiky ball it now has some spikes of its own and even though it is still flubber it is now the same rusty metal material of the spiky ball.