Homer Simpson

Homer Simpson once bounced through a test chamber with the Twelfth Doctor. (NOTVALID: Doctor Who Joins LEGO Dimensions) He later stood in a crowd of people, closest to Peter Venkman and Aquaman, before appearing out of a pink frosted donut with rainbow sprinkles, having been eating it.

A child then put his body back together and placed him onto a LEGO Gateway, with him then appearing in another test chamber, on a wrecking ball in front of a purple stud. (NOTVALID: Endless Awesome) When he met the Doctor, he asked who he was. The Twelfth Doctor told him that he'd offer him a jelly baby, but he'd take the whole bag.

A Cyberman told him that he was incompatible for upgrade, as they didn't stock Cyber-armour in his size. (NOTVALID: LEGO Dimensions) He once walked through the Brick Boulevard when the TARDIS, Ecto-1, and the DeLorean crashed into each other. (NOTVALID: Doctor, Doctor, Doctor)

Behind the scenes
Homer Simpson was a character in The Simpsons who appeared in the crossover video game LEGO Dimensions, hence his appearances being in a LEGO form.