Gatling Groinks, guardians of Bikini Bottom, are pretty scary fish monsters created to, "keep the peace" in Bikini Bottom after being rebuilt from that nuke, but since Bikini Bottom is a screwed-up ghetto town, it just shoots people who try to abide actual laws. The only passing reference of them being good is keeping Bikini Bottom safe from outside attacks, which wasn't even that needed since Bikini Bottom surviving was somewhat of a secret.
Gatling Groinks basically walk up and down the ruined streets of this lost city, when they choose to ruin somebody's day, they go off and find some doof and spin their tail a few times, and then reveal their mouths... which are ACTUAL GATLING GUNS! They shoot the person until they aren't even a hole in the ground, and then file a pothole complaint. It's just this every night. One can even say Bikini Bottom is better off without them.
Gatling Groinks have a windshield, but it's kinda useless as their eyes are on the side of their heads. Gatling Groinks are useful for one thing, however: unlike that dumb Armight they can stop Quadgun attacks. Your only hope of stopping Gatling Groinks is grabbing hold of their tails, if they don't spin it tricks the Groink into thinking it cannot spit bullets so it just goes up in an asplosion. Bring it to your Pikmin so that they can dispose of it's corpse before the bolted behemoth realizes it's not actually dead.
Some psychopath is also working on a subspecies called the Fireflinger Groink, which spits fireballs so hot they don't die out in water. Basically, don't even think of going to that one area in the Pacific, especially considering they can go on land...
Being bio-mechanical and scary, one was a member of the Scary Robots Gang, but left because of the seafood pizza Freddy Fazbear made to attract a Bottom Feeder. Now no Gatling Groinks will go near any member, one could say THEY fear the Scary Robots Gang!
It is said they were made in the likeness of former mayor Darwin Watterson... They didn't translate his looks all too well.