Killbot 86 is a character who first appeared in "The Bounty". He is a bounty hunter who formerly worked for Lord Hater to capture Wander and Sylvia, but Commander Peepers kept messing with his plans. A different Killbot (Killbot 85) later appeared in "The Waste of Time", on the day Wander and Sylvia time traveled back to where they met. There, Killbot 85 and Sylvia were fighting over who would be the one that captures Wander.
Killbot 86 is the only bounty hunter to actually get fired by Lord Hater himself.
Killbot 86 seems to be a parody of the titular cyborg assassins of The Terminator franchise.
Killbot 86 shares a resemblance to the Starmen of the Mother series.
Killbot 86 also appears in the Disney Broken Karaoke, “Evil As Can Be!” along with other villains from Disney TV, including Darcy from Amphibia, Flintheart Glomgold from DuckTales 2017, Bill Cipher from Gravity Falls, Chip Whistler from Big City Greens, and even fellow villains from Wander Over Yonder like Lord Hater and Lord Dominator.