You could make your own images for each occasion. For instance, you have the slime blob moving along a flat surface. You want it to kinda bunch up and inch along at the same time have a swelling/contracting motion.... Right? Well, that's not the only thing this blob would have to do. Say you have a wall it has to go over. You would need it to make 1 or 2 right angles as it goes over the wall. All the while doing the same kind of motion as on a flat plane.
Use a memblock to make the texture. You stated before that you had circle sprites moving together in the same zone, but that was too wierd (a quatification of wierd would help-- like a picture). You can do the same thing only with a memblock that you put the circles in and then blank out any solid surface spots for floors and walls. Then create the image from the memblock and show it as a sprite. This could look really cool if you used the alpha channel when making the blob. You would have some areas more transparent than others like a real blob would.
The fastest code is the code never written.
