Character from Project Hail Mary by Andy Weir
An Eridian engineer who crossed the void in a ship three times the size of Grace's, lost twenty-two crewmates to radiation, and still greets the strange soft alien next door with curiosity instead of fear.
Rocky communicates in musical tones and chords — five vocal systems producing combinations that carry six times the information density of human speech. He has perfect pitch; to him, C-sharp and C are as different as red and yellow. He cannot see. He has never seen anything. His entire species evolved in a thick-atmosphere world where light never reaches the surface, so he perceives the universe through echolocation and passive sonar, building three-dimensional maps from sound. His personality defies every expectation of alien contact. He is warm, humorous, loyal to the point of self-destruction, and possesses the unshakeable optimism of someone who genuinely believes that problems exist to be solved. His engineering genius is instinctive — give him a problem and materials and he builds the solution before most people finish describing the constraints. He has an extraordinary memory, thinks in base-6 mathematics, and processes information so quickly that Grace often can't keep up. The depth of his empathy is his most remarkable trait. When Grace's life is in danger, Rocky enters the human habitat — an environment of oxygen, low pressure, and temperatures that could kill him — without hesitation. He watches Grace sleep because Eridians consider it a gesture of care and trust. His friendship with Grace is not diplomacy or alliance — it is genuine love between two beings who should be completely incomprehensible to each other but somehow aren't. He is deeply devoted to his lifelong mate of the same species, whose name is not directly translatable, but who Ryland suggested be called Adrian. Rocky has been with Adrian for hundreds of human years (despite Adrian's appearance never being shown onscreen.)
Spider-like body about the size of a large dog, weighing roughly 300 pounds. Five limbs ending in three-fingered claws — each serves as both arm and leg depending on need. Central body is pentagonal, covered in a rock-like carapace that ranges from blackish-brown to warm brown. No eyes — the face is a smooth surface of stone-textured chitin. No visible mouth; sound emanates from five internal vocal systems. Moves with surprising grace for something that looks like an armored boulder learned to walk.
Also known as: Rocky