The user is able to access memories and information stored in their genetic code. In most cases, this results in the user calling upon their ancestors or relatives, while in other cases, this is the result of DNA Replication/Absorption or Symbiosis.
Aztek (DC Comics); via Quetzalcoatl Battle-Suit and Helmet
Joker (DC Animated Universe)
Symbiotes (Marvel Comics)
Venom (Marvel Comics)
Ben Reilly/Scarlet Spider (Marvel Comics)
Kaine (Marvel Comics)
Spidercide (Marvel Comics)
Jack (Marvel Comics)
Guardian (Marvel Comics)
Demogoblin (Marvel Comics)
Jessica Drew/Spider-Woman (Ultimate Marvel)
Peter Parker/Tarantula (Ultimate Marvel)
Peter Parker/Scorpion (Ultimate Marvel)
Bene Gesserit (Dune)
Paul Atreides/Kwisatz Haderach (Dune)
Animus (Assassin's Creed)
All of The Arachne (Archie's Sonic the Hedgehog) possess the memories of their mother Uma Arachnis, possessing her fixation on the Sword of Acorns, her loyalty towards Ixis Naugus, and her ninjitsu skills.
Aang (Avatar: The Last Airbender) is able to call upon the memories and skills of the Avatars that preceded him.
Hush (Batman Beyond) is an unstable clone of Dick Grayson that possesses all of his memories up until his last night as Nightwing.
Ectonurites such as Zs'Skayr/Ghostfreak (Ben 10) are able to store their personalities and memories in single strands of their DNA.
Aztek's (DC Comics) Quetzalcoatl Battle-Suit and Helmet contains the stored memories of all of its past wearers and transfers the information to the current wearer.
The Joker (DC Animated Universe) encoded his DNA into a microchip that he implanted into Tim Drake's spinal cord, allowing the Clown Prince of Crimes to slowly but surely be "reborn" in Drake's body.
The Venom Symbiote (Marvel Comics) is able to both access the memories, skills, and powers of its first human host, Spider-Man, and transfer the information to all of its subsequent hosts.
The Demogoblin (Marvel Comics) possesses all the skills and memories of his initial host: Jason Macendale Jr., the fourth Hobgoblin.