add the penguin

The Penguin would be a perfect mob to inhabit rocky shores, snowy biomes, and the new ice caves. When fed any fish, it swims to guide the player to the nearest shipwreck or ocean ruin—a feature far more useful than simply boosting boats. When two penguins are fed, one lays an egg on the ground (preferring ice blocks) and the other sits on top to hatch it, with the egg being collectible using Silk Touch. Additionally, adult penguins are protective and will attack anyone who dares to hurt their chicks

Dolphins already have a mechanic for reaching underwater structures, so perhaps the penguin could help the player reach the surface quickly by pulling them from the bottom of the water if they are drowning.This was a suggestion from a comment below, and I thought it was amazing.