Spoiler: This contains info from Hellboy VS Demonic Toys II, Chapter 3, The Hellish Nightmare. Except, I feel I should add a more scarier and disturbing aspect to it. Also, I would just reddit the chapter in the official original story, but this is another version, one removed from the original fanfiction.
Chapter 3: The Hellish Nightmare
Hellboy was having difficulties sleeping but he eventually got to sleep.
When he started dreaming he was by the asylum that Custer had died in maybe. Hellboy was actually happy because he couldn't wait to kill Custer. Obviously, it was a dream, but he still wanted to. He kicked down the door to the asylum and pulled out his pistol. "Kurtz! I know you're here!" Hellboy yelled. But not a sound was heard. Hellboy got closer in as he heard the door slam by itself. "Aw, crap!" He yelled. He then heard the laughing of Jack Attack. "How many times does he die and come back?!" Hellboy thought. "I know you're here, Kurtz! Show yourself!" Hellboy yelled. A picture flashed of Custer with blank yellow eyes, jagged teeth and much longer hair over Hellboy's mind, as a jumpscare. Almost randomly, Hellboy then saw Custer eye to eye. "Get ready to die, Kurtz!" Hellboy yelled at him. "I'm ready!" Custer said. As Hellboy went in to punch Custer, he disappeared. "Where am I? I'm over here! Behind you!" Custer said as he disappeared each time that Hellboy attempted punching him. Hellboy got tired eventually. He fell down in stress. He then thought "Hey! This is a dream! This is my imagination! Anything can happen in a dream." Suddenly, the room blacked out. Hellboy looked around until he fell into a hole. 10 feet down was a purple portal. Hellboy went in and he hit what looked like Hell itself! Bodies were everywhere. He would walk across a rickety bridge over a lake of lava, to meet with Despair, as The Devil. "Your time is near, Hellboy." The Devil said. "You actually think that your going to kill me? I'm fireproof for God's sake! I can't die in Hell! I'm half demon anyway!" Hellboy tried to explain. "This is where you will die." The Devil said. Hellboy then spotted a lava spill from the top of the red ceiling. "Ah, crap." Hellboy said. He was able to dodge the lava. Then, the worst thing that could have ever happened, well, happened. A cute little kitten, in colors of Black and White, was just walking. Just then, some kind of monster, in the color of Red, tried to jump at it. At that point, Hellboy pulls out his gun and tries to shoot this demon like thing. But, the kitten was just a hallucination. But he gets distracted by another thing. It's in everyone's favorite colors, Red and Black. It's got an ugly facial expression. It is no more than the Scarecrow Demon. That thing flew at Hellboy and tried to bite him. Hellboy shot at it but it didn't work. It was like a bird that wouldn't die. The last thing he could do was shoot a few bat demons, but his gun disintegrated into dust. The only thing he could use now was his fist. But the only things he could hit were the ground, the wall, the bat demons and the other demons. The lava began to flow higher. Out of the lava came an 8 pack of Hellhounds. They all had drastically different looks than Sammael. Instead, they were grey Dobermans with red glowing eyes. The Dogs bit Hellboy in every place you could possibly imagine. By the time The Dogs stopped, Hellboy was a mangled mess. He had his chest cut open and blood spraying everywhere. Soon enough, The Demonic Toys had a place in part. This time, it was just Grizzly Teddy, Jack Attack, and Baby Oopsie Daisy. Mr. Static and Zombietoid were not involved. Baby Oopsie Daisy knifed Hellboy, causing him to fall to the ground. Grizzly Teddy took a bite out of Hellboy's face, and Jack Attack did the same. Grizzly Teddy grew into his half monster form faster than usual. Just then, the lava came flowing far enough to touch Hellboy. He was burnt to a crisp soon enough. Shocking, isn't Hellboy fireproof? Well, not here apparently. Baby Oopsie Daisy took Hellboy's corpse out of the lava. Grizzly Teddy ate the remains, well, at least half of them. The Grizzly Monster helped himself to Hellboy's organs and guts. It was pretty much the end until--
"Red, wake up!" Liz said, trying to wake Hellboy. He rose up quick with an "Ow!" as if someone touched him. "Liz? What?" Hellboy asked. "You're dreaming, aren't you?" Liz asked. "First of all, how did you know? and two, when did you get here?" Hellboy asked. "Red, I was reading a book in here and you fell asleep, and by some coincidence, I did to." Liz explained. "You sure it wasn't just so you could be with me?" Hellboy wondered. "That was part of it. But I was reading when I fell asleep in here. I was reading about some demon." Liz explained. "Demon? Do you have any memory of the name?" Hellboy asked. "I think it was...Despair or something like that." Liz replied. "Does it say anything about him being able to turn into a devil?" Hellboy wondered. "Abe knows more about this. Ask him!" Liz replied. "I'm going to the fridge and getting a beer to forget about it." Hellboy said. "Well, at least the trip to Hell I had." He continued. He headed to the fridge for his beer and grabbed a Ruth while he was at it. But, when he was going back to bed around 6 in the morning, (he fell asleep at 5:25 am and Liz woke him at exactly 5:53 am) Liz wanted to know something. "You said you had a trip to Hell. Is that what your nightmare was about?" Liz asked. Hellboy didn't want to reply. He wanted to be the fearless man he always was and not share any details. "Red?" Liz said. "Alrighty, I'll tell you. But that doesn't mean tell everyone in the B.P.R.D, aside from Abe. He can know because I know you'll have no resistance to tell him. But if Manning was alive, would I want you telling him? Huh? Huh?" Hellboy asked. "No, but can you tell me?" Liz asked. "The most I can remember at the moment is Hellhounds tried to kill me. No, wait. That demon you were talking about? He's a shape shifter. He can turn himself into a devil somehow. He told me that I would be going soon. Maybe it is true. He'll kill me. Won't he?" Hellboy said. "It wasn't real, HB." Liz told him. "But I know I saw the demon, and he looks exactly like he does in this book." Hellboy said, holding up the lore book Liz had. "These Hellhounds are also pretty close." He added. "Remember Sammael? That kinda ugly guy? He was a Hellhound, I mean, his pals decided to jump on me and you had to save me." Hellboy joked. Liz smiled. "But, those Hellhounds, the ones that deserve the term Hellhound and look like dogs...they're the Satan's puppies." Hellboy said. "That's all I'm going to tell you." He said before he hit his pillow and faster than Liz could say "Red?" he was knocked out cold, snoring. Liz decided to sleep with Hellboy this time. Maybe Hellboy could shrug it off, but maybe a little scared, but soon enough, he'd get over it, but Liz still felt the temptation to stay in the same room.