Avery Bullock, Jr. was originally an Indian orphan named Sanjit.
When Francine becomes horrified at the thought that she was responsible for killing her friend Melinda in "Four Little Words", Francine leaves and moves to India, explaining that to amend for her crime she feels the need to help others and find redemption. While in India, Francine adopted a baby whose mother had died toiling to feed her family and her dying wish was for Francine to take care of her orphaned child. Stan eventually comes clean that he faked Melinda's death at Francine's hands to cover for his boss Avery Bullock, leaving Francine furious and concerned about what to do with Sanjit. Stan comes up with the idea to give it to Bullock to take care of to take his mind off of his missing wife who was a hostage in Fallujah.
In "One Little Word" Avery Bullock reveals that Jr. is making it a challenge to score with girls and passes Avery Jr. off to Francine, causing Roger to become jealous. When Francine becomes too frazzled dealing with the two of them, Stan hits on the idea of bringing Miriam Bullock back from the Middle East to deal with him. Miriam tries to take Jr. hostage due to being brainwashed, but when Miriam finds out the baby is hers, she warms up to him, briefly naming him "Muhammad". Roger is heartbroken that Avery was taken away and steals him back, but when Jr. breaks one of Roger's crystal spiders, he tries to drown him. Stan stops him and Roger concocts a plan to get them out of trouble by making it look like Coco, Bullock's latest fling, kidnapped the baby. Bullock and Miriam rush in to save Jr., but when Miriam finds out Avery has a mistress, shoots Avery in the kneecap and takes Jr. with her.
When expressing his final wishes to Stan in "The Full Cognitive Redaction of Avery Bullock by the Coward Stan Smith", Bullock instructs him to shoot him in the back of the head and tell Jr. that he just killed his daddy.
Avery Jr. is mentioned when Stan notes Bullock's attendance at "Familyland" without the baby.