Starfish!

What's inside:
⭐ 6 starfish colours: Orange (50%), Red (25%), Pink (10%), Sunny Sunspotted (7%), Black with White Spots (5%) and the glowing Bioluminescent (2.5%)
🌟 GIANT starfish: a 0.5% chance, in any colour
🍼 Babies and breeding: feed two starfish raw cod or salmon (babies take after mum or dad... usually)
🪣 Bucket of Starfish: scoop one up and its colour, size and age come with it
🏖️ Rock pools on beaches, with starfish living in them
🐚 Coquina: a real rock made of seashells, with stairs, slabs, walls, polished and chiseled blocks
🍯 Preserved Starfish: wax one with honeycomb and put it on floors, walls or ceilings (the glowing one is a night light!)
🌙 Bioluminescent starfish glow at night, and flare up if you get too close
🐌 Top speed: 1.75 blocks a minute. They are not in a hurry.

Find them in oceans (warm ones especially), on beaches, snowy beaches and stony shores. (Not rivers. They have standards.) Free to use in any Modpack!