The Jellien Clones look almost exactly the same as their Bikini Bottomites counterparts, except for a few traits. They have big, black eyes with white pupils and sharp teeth that are spaced from one another (even Jellien Patrick doesn't have Patrick's one tooth). Aside from those, the Jellien Clones look like a mirror to their counterparts and can fool anyone into thinking they are normal citizens.
The Jellien Clones are created when regular Jelliens, which the Evil Alien Jellyfish Overlord already made, attach themselves on top of the host's head, then squirt out a Jellien Clone in its place. The Jelliens then take the real copies away where the Jellien Clones live out their lives.
After SpongeBob and Jellien Patrick gave away Jelliens to everyone, the Jellien Bikini Bottomites started to take over. Like all Jelliens, they have big, black eyes and sharp teeth and talk in a slow manner. They spend most of their time at the Krusty Krab ordering Krabby Patties without mayonnaise.
Behavior and Weakness
The Jellien clones talk in a slow, monotone matter much like how aliens would talk. Some of them, mainly Jellien Squidward, would sometimes end their sentence with a "RAH" like sound. They even seem to act like their real counterparts, such as eating Krabby Patties. However, when someone mentions mayonnaise, they act extremely aggressive and attack on sight. They also seem to hiss and point at anyone that mentions the condiment. This is because mayonnaise is their one and only weakness. If touched by mayonnaise, the Jellien clone will melt into a pool of green slime and the bodies which they took over will wake up.
While lacking any ability to create Jellien clones, Jelliens Clones would attack in droves and fight to death for the sake of the Overlord's safety, as seen when they surround and try to attack SpongeBob and Sandy even if they eventually killed off by both of them with mayonnaise.
The Jellien Bikini Bottomites' real behavior when there are no ordinary lifeforms around is much different compared with their real copies. They mainly act like mindless zombies which, of course, are made to serve the Overlord. They also seem to enjoy hissing, especially when someone mentions mayonnaise. They also appear to walk very slowly like zombies but can also run very fast as they were chasing SpongeBob out of the Krusty Krab.
Given that they cannot create clones unlike Jellien Jellyfishes, they serve as Secondary Jelliens.
After SpongeBob said he hated mustard, Jellien Fred then said he like mustard. This may be that the Jelliens love all condiments except mayonnaise.