Frankenturret

"For god's sake, you're BOXES with LEGS! It is literally your only purpose! Walking onto buttons! How can you not do the one thing you were designed for?"

- Wheatley

Frankenturrets (referred to as such in the developer's commentary, no official name is given) are hybrids of Aperture Science Weighted Storage Cubes and two Sentry Turrets made by Wheatley during the course of Portal 2.

Overview
Wheatley designed the Frankenturrets to compensate for his lack of test subjects, having intended to design a cube which could walk on buttons themselves. However, they are shown to be utterly useless for that purpose, only wandering around aimlessly and falling over. After their introduction, they are used in place of normal cubes, with the only major difference between them and the standard cube being that the Frankenturrets will try to hop away if placed right-side up. This can be a nuisance in Wheatley's tests, but placing them so they land on their back negates the problem.

Trivia

 * Instead of speaking like standard turrets, they make an unusual chirping sounds, although they sound like sped up and gargled voice clips which can be roughly translated to "Let me think about this.", "What are you doing?" and "Up!".
 * When picked up, they tuck their turret bodies and legs into the cube.
 * Their cube fixtures feature a modified version of the Aperture Laboratories logo, reading "Wheatley Laboratories".
 * While they do not speak themselves, they do appear to understand speech, since a number were disabled by GlaDOS's paradoxical statement.
 * A Frankenturret can be seen crawling along near the back during the Turret Opera.

Behind the scenes

 * The developer commentary notes their withdrawing into a cube was initially just to make them be cubical when picked up, but it was so cute they added shaking animations and wide-eyed reactions to the turret to make the player sympathize with their plight.

List of appearances

 * Portal 2