Logic Goats

Now, through the power of paper (cheap and generally available) logic gates are available in goat form. Properly constructed from the DIY guide the AND goat will nod its head only in you press the right button and the left button. The OR goat, then, will nod its head in approval when the left button or the right button or both buttons are pressed. The NOT goat, finally, gives a friendly nod of the head when the button is not pressed.

www.flying-pig.co.uk/pagesv/logicgoat.html
www.youtube.com/elektorim