Malefactor
Malefactors were a form of archaic Tyranid transport organism hailing from that race's great and carefree youth, when their conquest of the 2nd-edition galaxy relied on a heinous ocular assault with painfully distorted shapes and completely perverse color schemes. The Malefactor itself relied on the spectacle of its insane nose/dong protuberance to confuse and amaze its opponents, holding aloft and displaying its great flabby shepherd's-crook arms to intensify the enemy's stunned disbelief. The creature was presumably then able to slide past its dumbfounded, vomiting, and/or hysterically laughing enemies to safely reach its target deployment zone.
This senseless eyesore of a Tyranid was designed to smuggle a nauseating quantity of its smaller brethren (old-fashioned Genestealers, Squats, Goblins a la Nilbog, etc.) into combat among the ill-favored folds of its hideousness. These would then be emitted via the Malefactor's transport sphincters (official term) in a totally indecent convulsion which would have made the universe itself twist to look the other way.