The 2% spawn-rate sign repairer below Dirtmouth, whose Hunter's Journal entry is the hardest secret in the game and whose private diary sits in his house above the well.
Menderbug is the rarest pacifist in Hallownest. According to the wiki, he has a 2% chance to spawn at the entrance of the Forgotten Crossroads right below Dirtmouth, and only after the sign on the left has been destroyed and the room reloaded. Upon seeing the Knight he immediately flies away.
Per the wiki, his entire purpose is to fix the signs of Hallownest. Before the Knight first breaks the Dirtmouth to Crossroads sign, it looks clean and well built. After the first break, the version that respawns looks haphazardly put together, because the Menderbug has been working overtime.
The wiki specifies that killing the Menderbug grants a secret Hunter's Journal entry. He has no boss music, no attack, and is generally considered the hardest required entry in the journal because of the 2% spawn rate plus the two-second kill window. The standard method is to enter the Crossroads from Dirtmouth using Desolate Dive (or Descending Dark) so the spell lands on his spawn point and the sign at the same time.
This guide covers the 2% spawn conditions, the Desolate Dive one-hit kill setup, the alternative Vengeful Spirit method from the side rooms, the late-game Kingsoul + Salubra's Blessing SOUL-refill loop, his secret Dirtmouth house and the private diary inside it, and the secret Hunter's Journal entry he unlocks.
The Menderbug, the bug who repairs the signs of the Forgotten Crossroads.
Crossroads entrance below Dirtmouth, after the left sign has been broken and the room reloaded.
Desolate Dive or Descending Dark from the Dirtmouth well, lands on the sign and the bug at once.
Secret Hunter's Journal entry plus access to his private diary in the house above the well.The Menderbug is Hallownest's sign-repair specialist. Per the wiki, his job is to fix the signs of the Forgotten Crossroads, and the sign he is most associated with is the one at the entrance from Dirtmouth on the left. Community sourced content confirms the wiki framing: his favourite sign is the one between Dirtmouth and the Crossroads.
According to the wiki, the Menderbug is technically classified as an enemy in the Hunter's Journal, but he is not infected and he does not attack. Upon seeing the Knight, he immediately flies away and leaves the room. The wiki notes the small visual joke: before the sign is first broken, it looks clean and well built. After the first break, the version that respawns looks haphazardly put together, because the Menderbug has been working overtime.
The wiki specifies that he has no Dream Nail dialogue and no combat behaviour beyond fleeing. He is a deliberately designed easter-egg NPC, hidden behind one of the highest spawn-rate gates in the game, with the secret journal entry as the wink to players who find him.
Menderbug does not spawn on a normal route. Per the wiki, the rate is a flat 2% chance per room entry into the Crossroads transition below Dirtmouth, and both of these conditions must be true at the same time:
According to the wiki, the sign is destroyed simply by striking it with the Nail, and the room must reload between every attempt. In actual play, this means each attempt takes about five to ten seconds (drop into the Crossroads, look, leave back up the well, return), and a typical successful run takes twenty to fifty attempts. Steam community posts cite outliers at over an hour of attempts; the 2% gate is real.
The wiki notes that once the Menderbug spawns, the kill window is brief. He immediately starts flying toward the exit on screen and disappears into the next room within roughly two seconds. The whole challenge sits in landing damage inside that window, which is why every recommended method below is a spell rather than a Nail swing.
Stand at the Dirtmouth well opening and only commit to the drop once the room reload starts. Per the wiki, the 2% roll happens on room entry, so the cheapest pattern is to fall, look, immediately Stag back to Dirtmouth via the bench, and repeat. In actual play, the Stag-based loop is faster than climbing back up the well because the bench warm-up happens automatically on each visit.
The standard kill is Desolate Dive from above. Per the wiki, dropping into the Crossroads from Dirtmouth while casting Desolate Dive (or its upgrade, Descending Dark) lands the spell on the sign and the Menderbug's spawn point in the same frame. The sign breaks (which makes the next attempt valid) and the splash damage one-shots the Menderbug if he happens to be there.
According to the wiki, this is the lowest-skill method in the game for the kill because timing is not required. The Knight simply falls through the well opening with the spell input held, and the spell discharges automatically on landing. The wiki specifies that Descending Dark works identically, with the trade-off that it costs the same SOUL but does more damage than needed (overkill on a 1-HP enemy).
The wiki notes a small wrinkle: the spell only kills the Menderbug if he spawned on this room entry, not the previous one. Running the attempt without checking the room state first is fine in practice because the Dive also breaks the sign as a side effect, so a wasted attempt still costs only one SOUL Vessel.
Two other methods exist for runs that have not yet unlocked Desolate Dive. Per the wiki, both work, but both are slower than the well-drop spell.
According to the wiki, the first alternative is the pause-cancel Nail strike. Pausing during the fall and unpausing repositions the Knight slightly, and the Nail can be used to land a strike on the Menderbug before touching the floor. The wiki notes this is finicky because the Nail has limited reach and the Menderbug is already flying.
The wiki specifies that the second alternative is Vengeful Spirit or Shade Soul from the east or west side rooms of the Crossroads. Entering from the side allows the spell to fire horizontally toward the sign area. The wiki notes this is the cheapest SOUL-cost method and does not require beating Soul Master, but it takes significantly more total time because every attempt requires walking to and from a side room rather than just dropping the well.
The wiki notes that the late-game easiest setup combines Kingsoul with Salubra's Blessing for fast SOUL regen between attempts, so the Desolate Dive method can run continuously without a bench break. In practice, this is the standard 112%-run pattern.
The Menderbug owns a house in Dirtmouth. Per the wiki and community-confirmed locations, the house sits to the left of Sly's shop, and inside is a small diary the Knight can read. The diary entries are short, mundane, and reveal that the Menderbug is genuinely proud of his sign work and considers the Dirtmouth-Crossroads sign his favourite.
According to the wiki, the house is empty during normal play; the Menderbug never appears inside it. He spends his time at his job site below Dirtmouth, fixing the same sign over and over. The diary is the only in-game place where his name appears outside the Hunter's Journal entry.
The wiki notes the design beat: the Knight can read the diary of an NPC the Knight has just killed, with no in-game acknowledgement. In real runs, this is the moment most players feel actively bad about the secret journal entry, which is the joke Team Cherry telegraphed.
The secret journal entry is the in-fiction confirmation of the Menderbug's job. Per the wiki, the Hunter's text reads, in paraphrase, that the Menderbug is a living bug who fixes the signs of the Forgotten Crossroads, with the sign between Dirtmouth and the Crossroads named as his favourite. The entry is not required for the Hunter's Mark in the standard count, but it is required for journal completion in the 112% checklist.
According to the wiki, a few other trivia beats sit around the Menderbug:
The wiki specifies that the Menderbug's house and diary remain accessible whether or not he has been killed. There is no in-game gating on the diary; the spectacle is entirely emotional.
Menderbug ties into the Hunter's Journal, the spell unlock chain, and the 112% completion checklist. These spokes pick up the connected threads.
Game data and screenshots adapted from hollowknight.fandom.com, used under CC BY-SA 3.0. Original content remains the property of the wiki contributors and Team Cherry.