Sens is usually depicted as Sans wearing the clothes of Ness, most notably his red cap, striped shirt, and sometimes carrying his baseball bat.
Sens actually almost never appeared in any rips, despite Megalovania and Sans is Ness being at one point two major memes on the channel and the character being popular even outside of the SiIvaGunner comment section due to both the EarthBound, Undertale and Game Theory vivid fandoms (and haters).
One of his only true acknowledgements is the rip Song That Might Play When You Fight Sans - Undertale which is called "Song That Might Play When You Fight Sens" on the album GilvaSunner's Highest Quality Video Game Rips: Volume 1, as well as its sequel The Other Song That Might Play When You Fight Sens. It also got a custom Super Smash Bros. fanfare in the form of "Victory! Sens" / Victory! Mother - Super Smash Bros. Brawl. He also appeared in the rip Hungry Pumkin - Pumkin World, though as the opposite of the usual joke (Ness in Sans' clothing). Although he does not appear in the "final" rip Title Theme & Ending - 7 GRAND DAD, two amiibos of Sans and Ness side by side can be spotted above SiIvaGunner's desk.
Sens was one of the first Figments materialized into the real world by the Voice Inside Your Head in "Prologue", before being immediately taken by the Patrol-Bots. As of "Loves the Ladies", he is still in captivity.