Alright so the first thing I did was remove the spider from the base. I cut off the snot connecting him to the base and then pulled the legs up.
I then used green stuff to make a skirt that had a slight angle on the top of it. The reason was so that the creature would be leaning back on the skirt.
You can also see in this image the way I tried to layer the skirt a bit to help give it a fluid look. I then made a ring, again using the green stuff and placed it on the outside of the base. I made certain to leave the knobs on the base alone. Those would be the foaming oxygenated nutrient material overflowing out of the pool. Almost as if the creature had sprung out, as opposed to just gingerly pulling itself free.
It should be clear as well the way I repositioned the tentacles by cutting and removing sections and then placing them in the green stuff. The goal was to "add length" the to the tentacles. I felt it helped as oppsed to just flipping them over, which gives a different kind of look, but I felt that by doing it this way, your imagination will allow you to wonder how many more tentacles are down there in the liquid, and how long are they really.
This one is a good example of that, because as opposed to the ones in the front that look to be coming straight up and out right next to the body, the two in back appear to come up from farther away and then move back toward the body to give help grant it some leverage or something as it prepares to either lift itself further or perhaps its leaning back to strike at this point.