Vertigoes

retains the coordinates of the last time it was placed
can be made into the Ender Myosotis

one-use teleport with the condition that you are in the same dimension as the saved coordinates

makes a player take 2x damage (from non-player damage sources) for each Fragility level

the Velocity potion gives Haste II and Speed, but also Fragility
there is an enhanced version that gives Haste IV, Speed II, and Fragility II

while in inventory, completing certain tasks may transform this and give you some benefits

obtained by drowning in a swamp biome
benefits on right-click you can put a special Plant Essence block with the pearl indefinitely (useful for scaffolding)

obtained by breeding 20 animals
benefits while in hotbar, you deal extra damage to undead mobs (equal to Smite IV)
disabled if you kill a Villager or an animal

obtained by killing 25 Drowned
benefits while in main hand, gain Water Breathing, on right-click you can place water
disabled if you kill any fish/water friendly creature

obtained by killing 13 villagers
benefits while in main hand, undead creatures can't damage you (still take knockback)
disabled if you cure a Zombie Villager

using it on Bedrock teleports you to The End
breaking a Beacon with it drops instead a Heart of Glass

in a 9×9×9 area of effect every player receives Regeneration II
glows and can be waterlogged
the potion effect can be changed by using a Lingering Potion of the desired effect on it