He is a large extradimensional creature who once ruled over his Dark Dimension before it was accidentally destroyed by Hulk.
Originally, he was very belligerent and territorial, caring little for the reasons beings came to his dimension but feeling they should all pay the price for crossing the forbidden border. He did however thank Hulk for opening his eyes and helping him finally confront the Undying Ones directly.
When a considerable threat arose, he was portrayed as being the voice of reason among brutes, and will join forces with potential adversaries if it means stopping that threat.
However, he is still a demonic warlord, an agent of chaos and a conqueror of worlds, threatening to commit genocide on a few occasions, and has likely done so in the past many times.
The Dark-Crawler's origins are unknown, but he is from an unidentified extradimensional realm, referred to only as the Dark Dimension.
Due to his dimension serving as a pathway to worlds beyond (such as Earth), the demons known as the Undying Ones sent several powerful beings to battle and kill the Dark Crawler (then known as the Night-Crawler). Eons passed and none were able to match the powerful demon.
Clashing with the Hulk
It wasn't until modern times that a cult worshipping the Undying Ones sent the Hulk to the Night-Crawler's realm. Unlike all past foes, the Hulk was more than a worthy opponent and even managed to revert the Night-Crawler's own sonic attacks, shattering all solid matter in the Dark Dimension, sending the two (plus one of the cult's sacrifices, Barbara Norriss) spiraling across the void. The Night-Crawler teleported them all to a safer dimension, and stumbled upon the realm of the Undying Ones.
The Night-Crawler turned his rage upon one of the leader of the Undying Ones, known as the Nameless One, and defeated them, becoming their master and making their realm his new domain.
Clashing with Doctor Strange
He was unwittingly summoned by novice sorcerer James Mandarin, who became possessed by the Night-Crawler (at this point known as the Slitherer) and decided to take over Earth. James' girlfriend Meredith was able to convince him to throw off the Dark-Crawler's control, and with some help from Doctor Strange broke free from the demon's control. The Dark-Crawler was banished back to his realm.
Galaxy Master and the Ravager of Worlds
Under uncertain circumstances, the Dark-Crawler was enlisted by Empress Daydra of the Sagittarians to help oppose the cosmic threat known as the Galaxy Master, possibly due to the entity threatening the Dark-Crawler's dimension at some point.
Alongside Torgo and the Amphibion, the Dark-Crawler was sent to engage the Galaxy Master's agent, the Ravager of Worlds, who was actually the Abomination. His power amplified even further by the Galaxy Master, the Abomination easily drove off the three warriors, who narrowly escaped. In order to combat the power of this Ravager of Worlds, Daydra and the three warriors decided to recruit the strength of a being that they had all encountered in the past -- the Incredible Hulk.
Naming themselves the Hulk-Hunters, they arrived on Earth where they confronted Banner who quickly became the Hulk. Before they could explain that they were just searching for the Hulk and not attempting to capture or destroy him, he attacked them. The Hulk fought off all three of them until Empress Daydra beamed down and revealed the true threat of the Galaxy Master. The Hulk agreed to join them.
When the Amphibion taunted the Hulk into another scuffle, Dark-Crawler and Torgo were forced to step in, holding back Amphibion and the Hulk, respectively. Upon arriving, the Hulk was sent to engage the Abomination, while the other three, now known as the Horror-Hunters, were sent to oppose the Galaxy Master directly.
As the rampaging Hulk bludgeoned the Abomination, the Galaxy Master's defenses weakened. In order to defend himself, the Galaxy Master summoned the Abomination to his side, but the Hulk was brought along with him. The Hulk attacked the Galaxy Master, while the Hunters fought the Abomination, from whom the Galaxy Master had removed his power amplification. When the Hulk destroyed the Galaxy Master, the Abomination collapsed in defeat as well. Everyone went back to their place of origin.
Second Encounter with Doctor Strange
He was later summoned yet again to Earth by the villain Yandroth with power usurped from Gaea. He was enraged and threatened Dr. Strange, ordering him to tell him why and how he was there, or he would destroy him, his planet and all who lived there.
When the Defenders defeated Yandroth, all those he had been summoned to Earth were returned to their respective realms.
Powers and Abilities
The Dark-Crawler is both a physically and mystically powerful demon, being one of the most impressive among his kind at the time. His powers are variable depending on his magical resources and perhaps his dimensional location.
He has a powerful tail covered (like most of his body) in armor, can travel across dimensions and shoot force blasts as well as sonic vibrations from his crown.
Being immortal and having lived for eons, this essentially makes him billions of years old, which he has lived in a constant battle against powerful beings across the multiverse, the only one who ever managed to challenge him being the Hulk, who he had a good fight with thanks to his physical but most importantly magical prowess.
Even while possessing another body, the Dark-Crawler was a match for a Sorcerer Supreme, mostly thanks to his Sceptre of Shadows, and after conquering the Undying Ones, the Night-Crawler learned many new magical secrets from them.
He has to have the ability to change size and shape at will, going from being around the Hulk's size or twice that (which is how he was depicted in his first appearance) to around 50 feet tall (as seen in Defenders Vol 2 #1), as well as shapeshifting his arms into tentacle-like limbs. He is normally bigger than the Hulk who is often around 7 to 8 feet tall.
He wields the Sceptre of Shadow (later known as the Sceptre of Shadows), which blinds his opponents in blackness. The sceptre is fragile (though originally it could only be damaged by light energy) but swiftly regenerates.
- None of his many titles and even his original name "Night-Crawler" are his true name, which remains unknown to this day.
- Regarding why he changed from Night-Crawler to Dark-Crawler, it's due to the X-Men member Nightcrawler gaining so much popularity, which resulted in this less well-known demon having his name changed to avoid confusion.