This tutorial explains you a simple method to animate a Leach. This is only a basic of the character animation, although with this basic method you can achieve realistic animation.

1. Model a Leach as shown in "Image1.jpg". You can also download my scene file "LeachModel (Web).mb".

               Image1.jpg

2. Draw a CV curve as shown in the "Image2.jpg".

               Image2.jpg

3. Select the "Wire Tool" and first select the object "Leach" and press "enter" key. Second, select the "curve1" and Press "Enter" key. Select the "curve1" and under the Outputs section in the Channel box set "Dropoff Distance[0]=20.

4. Select all the CV's of the curve and set a key at Frame1 as a starting position. Turn "Auto Keyframe Toggle" - ON.

5.At Frame 40, selecting the scaling too, move the pivot point to the lower bottom to the last CV and scale down.(Image3.jpg).

               Image3.jpg

6. At Frame 80, moving the pivot point to the top of the CV's and scale up the CV's to its original length. (Image4.jpg).

               Image4.jpg

7. Like this, you can repeat the animation at Frame 120 (shrinking) and Frame 160 (expanding).

8. Select all the CV's and in the "Graph Editor" flatten all the keys.(Image5.jpg).

               Image5.jpg

Now, if you playback you can see, the Leach contracts and expands mechanically. We need to add some secondary animation to it.

9. Select the "Leach” and make sure the pivot point is in the center of the object and unlock the ScaleX attribute.(Image6.jpg).

               Image6.jpg

10. Key these values and ScaleX attribute of the Leach. Frame1=0.7, Frame40=1.2, Frame80=0.7, Frame120=1.2, Frame160=0.7. Now, you can see the mesh gets thicker as it contracts and gets thinner as it expands.

11. Add some in-between keys to the CV's to give a uneven motion to its body movement.(Image7.jpg).

               Image7.jpg

Play around and have fun.

You can download the completed scene file "Leach Animation.mb".