This tutorial will teach you how to create a paper tentacle effect with mainly filters.

Ok, first create a new document. File > New. You can use any size but for this I used 400x400 pixels.

Fill the background black by going, Edit > Fill > Black.

Now press CTRL + D, this will reset you background and foreground colors to there default settings of Black and White. Select the Gradient Tool and look at the toolbar. There should be a drop down menu like the one below. Select difference, as your blending mode.

Now, its time to go wild with your Gradient Tool, hold down the left mouse button move the mouse and then let go. It should create this kind of effect.

Keep doing that until you have something like this.

Next go Filter > Stylize > Find Edges. It should look like this.

Now press CTRL + I, this will invert the piece and should leave you with something like this.