I'm trying to construct this organism in my world, that is completely biological, but is almost like a large human-esque brain organ with slug-like apparatus extending from it. Like multiple tentacles and minor organs for sight and sound, and overtime these "tentacles" form the basis for piezoelectric muscles for movement and "growing" over something, which is where I lead to:
The idea is human and fellow cyborg crews grow these brains from infancy till they're large enough to have metallic plates, hydraulics, rotary things that these tentacle-muscles can grow upon and their "body" to essentially become humanoid in shape and action.
Its brain organ is slightly smaller than ours, but its neuron compression and incredible muscles allow it more processing power and strength than us, they just require facilitation into the world.
The origin story is they're sentient organs made to be implanted into spaceship components and cyborg bodies as long-living servants. They were grown upon the surfaces of planets and inside large biolabs so they're completely natural, but in their super-tech days these brains would barely need its tentacle-muscles for anything, thus its smaller size compression allowed greater productivity.
Basically my question is surmised, how feasible would these creatures be overall with a mechanical chassis essentially built around their bodies?