This is another original species: Bone Orcas!
Living in the waters under the ice caps of neptune these titanic creatures live by themselves apart from when mating season comes around. Most come in dark and light patterns hence there kind being named after orcas (even if the colours are inverted). There most prominent feature is there heavy bone plating along there backs and heads they use for both defence and breaking the ice to breathe! Unlike most water based mammels they swim in an undulating motion to save energy. When what its hunting enters a cave it cannot follow Bone Orcas use there prehensile tongues to reach in and grab it with ease!

Also yes this is open make as many as ya want ^w^