“Deep One Hybrid” is an inherited template that can be added to any living, corporeal vertebrate creature (referred to hereafter as the base creature) that is not a deep one or a deep one scion. In the majority of cases, deep one hybrids are humans or other humanoid creatures, but dolphin and alligator hybrids are not unheard of. Deep one hybrids of other creatures (such as supernatural monsters) are possible but incredibly rare. A creature that isn’t an adult does not gain any of the benefits of this template, but manifests them automatically within 1d4 weeks of achieving adulthood.
Hybrids younger than this are indistinguishable from typical members of the base creature’s species. (At the GM’s discretion, certain magical divinations or rituals or technological procedures can reveal the truth.)
Challenge Rating: Same as the base creature.
Type: The creature gains the deep one subtype, but does not gain all deep one traits—only those mentioned below are gained by a deep one hybrid.
Senses: Deep one hybrids gain low-light vision.
Weakness(es): All deep one hybrids gain the following weakness.
Sea Longing (Ex)
Speed: Deep one hybrids move with a shuffling gait. Their base speed is 10 feet less than the base creature’s speed, to a minimum of 10 feet.
Special Qualities: As base creature, plus deep one hybrids gain the following special qualities.
Final Change (Su)
Within 1d4 weeks of a deep one hybrid reaching old age, it undergoes its final, painful metamorphosis and becomes a deep one scion, gaining the deep one scion template (see below). A deep one hybrid can sometimes spontaneously undergo the change long before reaching old age—death by drowning always causes the change to occur early, as can prolonged periods of insanity or exposure to eldritch energies or the presence of certain agents of the Mythos at the GM’s discretion.
Hold Breath (Ex)
A deep one hybrid can hold its breath 10 times longer than a human can.
Sandy Petersen’s Cthulhu Mythos, © 2017, Petersen Games; Authors: Sandy Petersen, Arthur Petersen, Ian Starcher.