I've seen these but with a 2.5G corny keg. My local mom-and-pop shop owner says he took it in a backpack to a Halloween party. People just poured beer off his back. LOL
https://www.ontariobeerkegs.com/New_Ball_Lock_Keg_w_Single_Handle_AMCYL_2_5_Gal_p/2.5-single-acmcyl.htm
Seriously, if I was...