Hwurmp

"Tiny and placid but swells to enormous size when threatened. Extremely amusing creature."

Hwurmps are enemies in Hollow Knight. They are tiny creatures who have powerful, expandable lungs which allow them to swell up to an enormous size.

Behaviour and Tactics
Floats around passively until the Knight approaches them, after which it will slowly float towards them. Upon taking damage or colliding with an enemy or the Knight, it will inflate and bounce off objects, walls and water surfaces. After a relatively short period, they will revert to their original form. If they inflate inside a tight space where their inflated body cannot fit, they will instantly die.

Be careful when dealing with them in bigger numbers as they inflate each other upon contact and groups of them can easily and quickly fill up a room.

Location
They are found mainly in the north of Royal Waterways. Some can also be seen in the lower part of Isma's Grove.

Trivia

 * The Hwurmp is one of the few enemies to respawn upon leaving and re-entering the room.
 * An early screenshot shows the Hwurmps in Isma's Grove with a green colour instead of pink.

References

Бульк Hwurmp Hwurmp Hwurmp