You trace your ancestry to a terrible abomination of Yog-Sothoth.
Class Skill: Perception.
Bonus Spells: faerie fire (3rd), invisibility (5th), magic circle against law (7th), dimension door (9th), plane shift (11th), summon monster VI (13th), greater teleport (15th), summon monster VIII (17th), gate (19th).
Bloodline Powers: Yog-Sothoth sorcerers take on a strange, writhing aura when using their powers.
Starting at 1st level, you can grow a mouth on a stalk from any part of your body as a swift action. This is a primary bite attack that deals 1d6 points of damage if you are Medium (1d4 if you are Small). At 5th level, the bite overcomes damage reduction as if it were magic. At 7th level, you gain a +2 bonus on combat maneuver checks to grapple with the mouth. At 11th level, you can make a free combat maneuver check to grapple a creature you hit with the bite attack. You can use this ability a number of rounds per day equal to 3 + your Charisma modifier. These rounds need not be consecutive.
Flickering Gate (Su)
At 3rd level, you can open a portal connecting two points you can see within 5 feet per sorcerer level of each other and within that range of you until the end of your next turn as a standard action. Each portal is a transparent 5-foot cube that does not interfere with movement or effects. You (and only you) can move from within one cube to within the other by using 10 feet of movement (as if moving 5 feet into difficult terrain). If a creature begins its turn in either location, it falls into the other location unless it succeeds at a Reflex saving throw against DC 10 + 1/2 sorcerer level + Charisma modifier. If the destination is dangerous, the creature gains a +4 bonus on its saving throw. You can use this ability once per day at 3rd level, twice per day at 11th, and three times per day at 17th.
Reckless Summoning (Ex)
At 9th level, you can cast summoning spells with a casting time of 1 round as a standard action. When you do and the spell is at least 4th level, an uncontrolled outer mutant is also summoned adjacent to you and has a chance of attacking your apparent enemies equal to 60% + 2% per sorcerer level. Otherwise, it attacks your apparent allies—it does not target you unless it opposes you and cannot locate any of your allies. If the spell is at least 8th level, instead an uncontrolled outer abomination appears.
Endless Magic (Ex)
At 15th level, you gain an extra 7th-level sorcerer spell slot. At 18th level, this spell slot migrates up one spell level, becoming an extra 8th-level spell slot.
Living Gate (Ex)
At 20th level, your body is infused with interdimensional energies. You gain the aberration type and are no longer affected by spells and abilities that specifically target other creature types. You gain spell resistance 30 against unwanted abjuration spells.
Sandy Petersen’s Cthulhu Mythos, © 2017, Petersen Games; Authors: Sandy Petersen, Arthur Petersen, Ian Starcher.