Sorry for the double post, but this is an explanation of how i make a tentacle in Construct 2 :
1) I create a ball, called T1 for example, that i put in my game layout.
2) I duplicate it 4 times, i call them T2, T3, T4, T5, and i put it in a hidden not used layout.
3) In the beginning of each level, i first create a variable set to 1. This var will be the Tentacle class number.
Then, i perform a "for each" on the T1 sprite, and i create the T2, T3, T4, T5 sprites, assigning them in an instance variable the X and Y position of the 1st tentacle ball, and the tentacle class number. I reduce the size of them
proportionally, and i increment by 1 the Tentacle class number at the end of the "For each".
I also initialize a global variable, an Angle for the tentacles moves.
4) Next, in the game loop, i have just to target T1, T2, T3, T4, T5 when they have the same class number, and apply them my formulas around the Angle.