In April, 2013, it was announced that Portner had formed the group Avey Tare's Slasher Flicks along with Angel Deradoorian, former member of Dirty Projectors, and ex-Ponytail drummer, Jeremy Hyman. Portner describes the band as "[a] group of three hippies on a road trip through the backwaters of 2013s rural music scene fall prey to a murderous cannibalistic band making..." Their debut album Enter the Slasher House came out internationally on April 7, 2014, and a supporting west-coast tour was announced soon after the album's release. Ahead of the album they released a video for ‘Little Fang’ directed by Portner's sister and featuring a puppet created by Jim Henson’s Creature Shop. In 2017, he appeared on Grateful Dead member Mickey Hart's solo album, RAMU