Brain first appeared on Lil Dicky's 2015 debut album Professional Rapper, featuring on the track "Pillow Talking".

TJ Francis, in a piece for lifestyle website BroBible, wrote that the character allowed Lil Dicky to "dive deeper into his own mind and show off a different side".

Hot New Hip Hop's Mitch Findlay praised the "banging instrumental" and Lil Dicky's "signature blend of hilarious wit and capable flow".

Aron A., writing a review for HotNewHipHop, deemed this EP "another confirmation of Lil Dicky's creative brilliance".

[7] XXL's Nick Mojica gave a similar view, writing that "although Brain is still used for comedic relief, Dicky once again flexes his lyrical prowess on the project".