Frog Leg

The height boost is the advertised part, but the auto jump is what you will notice. Hold the key down and you hop continuously with no timing at all, which turns crossing broken terrain into one held button. It also raises how far you can fall before the ground hurts you, and that quietly prevents a lot of early deaths in the first deep cave dive.

Jump bonuses only apply to jumps taken from solid ground while unmounted, so once you are flying full time it stops contributing much. It still works while wings are equipped, which is why it stays on the loadout through the middle of the game rather than being replaced outright.

Everything it tinkers into keeps the jump and fall benefits, and those upgrades add together rather than overwriting each other, so building it into something bigger loses nothing. It fishes up in any decent body of water, so it is one of the few early accessories you can go and get on purpose instead of waiting for luck.

Despite the name it has nothing to do with the frog critter or the cooked dish.