Grendel considers Vandal Savage to be his father and Scandal Savage to be a half-sister of sorts, claiming that Vandal Savage "mounted my cavebeast of a mother."
Grendel is a character in the epic poem Beowulf.
Major Story Arcs
Wonder Woman: Ends of the Earth
When Wonder Woman was approached by Stalker the Soulless and given the task of killing D'grth, the dark god of warriors, Grendel was aiding D'grth in his dark plans. Wonder Woman and her allies, Beowulf and Claw the Unconquered, were forced to battle several people who had come to worship Grendel and were subsequently empowered by him.
Wonder Woman, Beowulf, Stalker, and Claw eventually came to confront D'grth at the edge of Stalker's world, with Grendel there as well to oppose them. It was then that Stalker told the heroes that their souls were being traded to D'grth for his. Stalker threw his sword at Wonder Woman, only for Beowulf to jump in front of her and be wounded instead. Claw was forced to fend off Grendel before he could tend to Beowulf's wounds, while Wonder Woman stole a shard of the Rock of Eternity to transport herself to Earth along with D'grth and ultimately managed to defeat him. Grendel however, later ended up on Earth, using the dimensional gateway that had just been opened with the Rock of Eternity.
Secret Six: Depths
Grendel later resurfaced in the hands of Mr. Smyth, a rather insane visionary who sought to build an enormous prison that existed in a legal limbo where all interested countries could throw away their undesirables. Smyth's grand vision was to base this prison on Hell as described in Dante's Inferno, for which he needed the Devil to reside at its heart. To this end, Smyth had managed to locate and capture Grendel to serve as this devil. Smyth then hired the Secret Six to safely transport the container that housed Grendel to his prison.
Unfortunately, Smyth's lieutenant, Emil, adored Grendel and sacrificed himself to free the beast. When the Secret Six began rebelling against their employer and Wonder Woman had arrived to investigate the presence of Amazons in the prison, Smyth bartered the now captive Wonder Woman to Grendel in exchange for his help in destroying his enemies. Grendel agreed to the deal and went to find his new prey.
Grendel "accidentally" killed several of Smyth's guards while looking for his opponents. He then fought Bane and a Venom-enhanced Scandal Savage, only to defeat them with relative ease. However, it was then that Wonder Woman broke free and killed Grendel by coming up behind him and breaking his neck, stating that he was not a human but a demon, allowing her to use lethal force.
Grendel appeared in the backup story in Sword of Sorcery, as a monster attacking Wiglaf's village. Wiglaf is sent out to retrieve Beowulf to slay the beast.
In this continuity, Grendel is a creation of a laboratory in order to create a super soldier in order to be able to fight against super humans.
Powers and Abilities
Grendel is a beast with immense strength and durability. He is also considerably faster and more agile than his size would indicate.
Grendel seems to give off an unnatural presence, one that seems to subtly influence people around him, as shown by the innate sense of fear that both Scandal Savage and Bane felt while in Smyth's prison, as well as how certain people seem to blindly take to worshipping him.
Grendel also seems to have an inhuman sense of smell, although it's unclear whether this is purely based on his sense of smell, or whether there is some mystical quality to it. He once sensed Beowulf's approach in time to lay an ambush, and could smell Wonder Woman's presence despite being isolated far away from her. It was shown by Wonder Woman however, that one could 'stay downwind' from this sense and catch Grendel by surprise.