Yes, actually, you can.
http://www.flay.com/text/clipmorphing.htm - as for a 'blunt' tenticle on the slowly revealed end, add for example a 'tip' that follows the morph path for add a 'tip' to the clip map. The next technique follows the theory paragraph (I'm wordy)..
Theory: With proper camera angles and cuts you can show a tenticle wrapping around a person without actually doing it. Take this for example: You want the tenticle to start expanding so cut to a close up of the wrist and run the effect to her ankles on one side. Cut back to the speakers for a few seconds or more, cut to the chicks waist with a tenticle peice wrapping around there, cut back to the speakers shot, run a tenticle through the shot around her back and so on. In the end, you'll have not shown the entire wrapping effect but just enough that people know what's going on. A little more creepy also. How to do it?
Morph targets as you noticed go straight from 1 target to the next varied only on time (keyframes)- they also only really act on points, that I've seen. So why not make multiple morph targets starting where the previous morph target left off? Tried the idea and surprisingly it worked and should work in Morph Gizmo or whatever ships with 6.5. Make a disk running up Y with 4 segments on the X axis. For all points in the bottom-most segment, highlite them and make a selection set or part and name them all like extrude_1 then deselect them and select all points on the next X segment up the Y path and name them like extrude_2 and work from the bottom to the top until all 4 segments have a name and are a point selection or part. Now totally flatten it all on the Y so all points are in the same Y space (set value on Y works nice for this).
Now to make it all work. Segment 1 is the base, it stays put. Create a new Morph named say Grow.1 and pick points using 'w', choose all your selection sets or parts from segments 2-4. Move it where you want and write the X,Y and Z positions down (and rotations if using them). Starting from the base create another morph Grow.2, pick sets 2-4, move them to the exact position you wrote down and deselect set 2 then move 3-4 up or somewhere and write the XYZ down again. From the base create another morph, Grow.3, pick sets 2-4, position set 2 at the same place as before, set 3 as the same place just previously written down and move set 4. When all morphs are applied in sequence, growth along a set path. Snakey squiggles and junk can be applied via more morphs or keyframing the created morphs (probably faster just keyframing- or I guess you can just offset say segment 2 a little while morphing segment 3..
The advantage of using the theory with the above is you only need to make morphs for the snaking shots and can use a one-peice object that kinda resembles the morphs for the last 'gonna squish you' shot. Or I guess you could run the whole tenicle out with the morphs with point sections in between each morph point..
You can make it all work Colto, looking forward to your idea.