Balloon Pufferfish

It does exactly what the Shiny Red Balloon does and it comes out of the water in any biome, so it is often the first real jump upgrade a fishing character gets hold of. The extra height changes how you move around: gaps you used to bridge with blocks clear in one jump, and cliff faces you had to tunnel through become climbable.

Identical in effect does not mean interchangeable at the anvil. This one only combines with the Tsunami in a Bottle, which is the one double jump item the balloon refuses, and the balloon takes every other one instead. Work out which combination you are building toward before you commit either half to a recipe, because the two are not swappable afterwards.

Below the surface it works against you slightly, shortening your jump instead of extending it. Not enough to matter unless you are trying to leave the ocean floor in a hurry.