He first appears in "All Your Fault" while being made by Lemongrab by squishing all the Candy Seeds together and pouring life-giving formula on them, after which Seed-Wad opened his eyes and promptly vomited up the excess formula, then immediately looked quite startled by his own existence. After this, Lemongrab exclaimed, "Ha ha! We'll call you Seed-Wad!" For the rest of the scene, he is shown still sitting on the table with a bewildered expression on his face. Seed-Wad has Lemon People DNA, but he is made up of candy seeds so he is also part Candy Person.
Seed-Wad looks like a bunch of candy seeds together with a face on them. At times, Seed-Wad has green vomited-up formula running down his mouth.