This here is Gordon, along with his guardian, Sirius.

As said in a previous picture with Gordon, he was abducted by aliens and was fed pills to give him basic knowledge, but this came with a terrible side effect. The side effect somehow "erased" almost all of Gordon's emotions- leaving only the first four emotions, Joy, Anger, Sadness, and Fear.

The alien species, characterized as tall, faceless, beings of energy, was both baffled and worried about Gordon. They knew he cannot live on his own, knowing he's missing certain emotions and with only four emotions, he could never function properly. After a quick session of brainstorming, they eventually came up with the most logical reason that'll work- giving Gordon the missing emotions via a guardian transferring them into his brain as the alien species is capable of transferring thoughts and feelings onto another being.

Accepting the idea, they appoint Sirius, the alien you see in the picture, to join Gordon and his trip down to Earth. When the time is right, He puts his hand on top of Gordon's head and transfers an emotion, thus giving Gordon a new emotion and eventually giving him all the emotions lost.