Levistus's_Leviathan
5e Freelancer
I hold the opinion that you should be able to play a Ceremorph, as the Gnome Ceremorphs from Icewind Dale: Rime of the Frostmaiden (which are adorable, by the way) can be any alignment.I think all of this fine.
Among the race traditions, probably the Thri-kreen is the least anthropomorphic?
There is room for nonhumanlike Aberrants.
I think of the tentacles, mouths and eyes as "soft" and boneless. But an insectile "hard" exoskeleton can make sense too.
Your avatar image reminds me of a human melding with Aberrant magical armor. The armor seems like a blend of skeletal corpse, exoskeleton, and sea creature, a great image for a Far Realms item.
I'd have it be an Aberration-type Lineage similar to the Dhampir, with its Extract Brain/Tentacles attack being similar to the Dhampir's Vampiric Bite (but Intelligence-based for attack and damage rolls). They'd also get telepathy and possibly a minor psychic-wave feature, but that'd be about it.