I was not satisfied with either US eyes or a Ledmatrix.
With some -rather rough- modifications I was able to position the 16x8 Led matrix as a mouth underneath the eyes.
I studied ways to have US sensor, buzzer, pushbutton and ledmatrix and I found as the best way this wiring:
A0 = Pushbutton (switches to +)
D0 = GPIO16 US Echo pin
D1 = GPIO4 SCL (I2C)
D2 = GPIO5 SCA (I2C)
D3 = GPIO0 Right Foot
D4 = GPIO2 Right Leg
D5 = GPIO14 US Trigger pin
D6 = GPIO12 Buzzer pin
D7 = GPIO13 Left Foot