"Chaka from Black Lagoon is a sociopathic asshole whose specialty seems to be Kicking the Dog and who sees nothing wrong with beating a noncombatant just to provoke his colleague into a gunfight, then running away while toting a human shield when things go badly for him and shooting several of his henchmen just because he's pissed. He fancies himself a Wild West gunman, but he's nothing more than a stupid, incompetent prick who thinks himself something far more than what he actually is. So much so that when he's finally dealt with, it's by Revy denying him his duel with her and leaving him for Ginji Matsuzaki, who relieves him of his gun and both of his hands before sending him into a pool to drown."
"The mayor in Advance Wars: Days of Ruin. A non-humorous example who gets a well-deserved Karmic Death near the end by trying to bargain with Big Bad Caulder to save himself after selling out the heroes to him."
Bloodivores had Ifen Cho, who not only murdered five men she was married to, she pushed Anji Zo towards one of the monsters just to save her(Ifen's) own skin only to find herself at a dead end.
Likely why she got abandoned by the protagonist, Liu Mi, who was carrying a wounded Anji to safety.
I think Aria from the beginning of Akame Ga Kill qualified, especially when this seemingly sweet little girl turns out to be a torturous rich bitch with the mask of an angel, if that doesn't convince you, watch the following scenes again with her true colors in mind:
1.Tatsumi was ordered by the last remaining guard to hold off Night Raid while he protects Aria in the family shed(Essentially turning him into a meat shield when you think about it), only for that guard to get the upper half of his body slashed off by Akame, followed by Aria falling off her feet where she's at Akame's mercy.
2.Aria tries to wander off after the shed is revealed to be a torture chamber only for Leone(who was trying to show Tatsumi who Aria and her family really were) to pull her back by the hair.
3.Aria tries to deny being involved with torture only for Tatsumi's friend Ieyasu(who was alive but dying) to testify that Aria tortured their(His and Tatsumi's) friend Sayo to death.
Afterwards when Tatsumi butchered her in retaliation for what she did to his friends, she didn't face death with dignity.
Kohei Shimoda/Paul Keen, one of the murder victims from the Detective Conan/Case Closed Episode "Ski Lodge Murder Case"/"Massacre Night", entered a panicked state after seeing the late Minako's name(in Japan)/Massacre Night(In English) on two victims of attempted murder and Sugiyama/Larry Sullivan(the other murder victim).
But when you realize that he and Sugiyama murdered Minako Mochizuki/Moreen Manahan and made her death look like a suicide to keep a fraud they were involved with under the rug, it could make Shimoda this, by the looks of his corpse, he never faced death with dignity.
‣The victims of the two part episode"Billionaire Birthday Blues"/"Wealthy Daughter Murder Case", Reika and Yuji Nikaidou/Steve Sloan, could qualify as they stole the life vest of the late Yaeko Nanao/Sonja, which led to her drowning, if the faces of their bodies are any indicator, neither faced death with dignity.
The Danmachi character Canoe Belway, the fat scumbag who treated Lili like dirt(to the point that he had no problem using her as bait for deadly ants just to save his own skin), could qualify as one, if that doesn't convince you that he's a coward, look at Fatso's reaction when cornered by the minotaur(one that Ottar trained earlier) prior to his death.
Higurashi: The moment Keiichi strikes him with a baseball bat, Teppei Hojo, who abused children, attempts to flee.
Strider(Manga): When Kuramoto turned out to be still alive and ordered him to surrender, the last thing Matic did was threaten everyone present with a bomb, but he(Matic) gets impaled by Yggdrasil, during which, he didn't face death with dignity.
Prizewell City Slicker from Heavy Object for several things:
1.He was implied to be behind the killing of members of foreign language bands, and foreign language school bombings, yet there was no evidence.
2.He had Nutley sabotage the 37th Legitimacy Kingdom military division's attack on the Kamchatka Peninsula, which led to the death of the 37th division's Charles and Charlotte Zoom getting injured.
3.He attempted to massacre a group of slave miners who tried to flee to the Legitimacy Kingdom and manipulate the information(both of which failed).
4.He had six a.i.-controlled objects aid him in the destruction of the Snowquake and Active Sledge Objects(along with the 37th division's base) and dealing heavy damage(no pun intended) to the Baby Magnum, which allowed him to proceed with the attempted massacre of the immigrant city.
5.Finally, when his attempted massacre on the immigrant city was foiled and his object gets destroyed, HE DOESN'T FACE DEATH WITH DIGNITY AT ALL!
Tales of Vesperia: When Alexander Cumore fell into a quicksand pit while running from Yuri, he begged for a rope, but since Yuri knew how much of a complete and utter scumbag Alex was, he left him to die.
Miwa Sakimori, the General Ripper from Daimos, wastes his time by not only shooting harmless brahmins , but also hiding behind his own men or the titular mech.
From Bait 3D, we have, Kirby, the robber who murdered a woman at the beginning, make an attempt at using one of the survivors as bait only for Doyle to attack him and use him as bait instead.
•Likewise there's Kyle, the Jerk Jock who was willing to sacrifice his girlfriend's poodle to try and save his own petty ass.