Aside from its poor speed & mobility (outside of water), the Octopus Girl's stats are well-rounded with particularly high growth in lust damage, making it well-suited for a tanky seducer role. It has three seduction-based skills natively. Its fixed skill GhostWrap does 1x lust damage, has 4 range, and entangles the enemy for one turn, or for two turns if the enemy is in shadow. Contrast with its possible skill Constrict, which does 2x lust damage, has only 1 range, and can only entangle an enemy for one turn. Entice has a range of 3, and reduces the lust resistance of its target by 3 while making the AI prioritize targetting "presenting" characters. Note that the Octopus Girl's low beauty can hamper its ability to serve as a recruiter without investing numerous Beauty Potions into its genealogy.
Aquatic and ShadowBound require that the Octopus Girl choose between utilizing water tiles and shadow tiles. Being in water tiles will remove any combat penalties for being in water, while preventing the Octopus Girl from being engaged by non-aquatic enemies, but will cause the Octopus Girl to be weakened (-40% strength) and slowed (-2 speed) when starting a new turn. The trait Telekinesis can offensively utilize and the skill ShadowForm (if bred onto the Octopus Girl) can defensively utilize the Octopus Girl's superior magic growth, foregoing strength entirely for further tanking/superior "spellblade" melee. In this way, Octopus Girl is one of the few shadow species that can operate competently without shadow tiles.
Alternatively, being in shadow tiles will allow the Octopus Girl to utilize its "ShadowArmor" and "SpreadShadow" passives, in conjunction with its fixed skill GrowShadow to absorb enemy attacks while debuffing them with curse without sacrificing a skill slot or its strength (in the case that you don't have Telekinesis yet). Being in shadow also enables use of ShadowStep and ShadowBond for flexibile mobility with the rest of its team. Shadow Attack can be used to help get the Octopus Girl into position for a MassCurse attack or for tanking.
None of their skills give them special abilities in portals.
They have the lowest virility among shadow species, and just about the highest fertility among shadow species. Their base beauty is low.
They have the same semen capacity as most other shadow species. Like most shadow species, they can be farmed for dark matter and have a meager 4 milk capacity.