A jarred bug rescue arc that spans every region of Hallownest. 46 trapped Grubs, one crying patriarch, and two Charms that fall out the other end.
Hollow Knight's Grub hunt is the largest collectible sweep in the game. Per the wiki, "there are 46 Grubs to be found in total" trapped in glass jars across every named region of Hallownest, and freeing them is the only way to access the two Grubfather-gated Charms (Grubsong and Grubberfly's Elegy) plus the Metamorphosis 112% achievement.
According to the wiki, the rescue mechanic is simple: "they can be freed by breaking the jar with the Nail, after which the Grub burrows into the ground and returns to Grubfather." Each jar pings a faint crying sound when the Knight is close, so the audio cue doubles as a "something hidden in this room" flag. Once a Grub is freed, the next Grubhome visit pays out the milestone reward at the new total.
The wiki specifies the lurking trap: Grub Mimics. "It is possible to come across a Grub Mimic trapped in a glass jar that transforms and becomes hostile when freed. The easiest way to check if it is an actual Grub is to Dream Nail them. Grubs always say '...Home...' but Grub Mimics say '...Kill...', '...Empty...' or '...Other...'." Dream Nailing every jar before swinging the Nail at it is the only safe pattern.
This guide covers the full 46-Grub region breakdown, the Grubfather milestone reward table (Geo at the low end, Pale Ore and Charms at the high end), the Collector's Map that surfaces unfreed Grub locations on purchased Maps, the Grub Mimic Dream Nail check, and the "Happy...happy...happy!!!" finale chain when all 46 are home.
Grub, a jarred creature freed by breaking the jar with the Nail.
46 total, spread across every Hallownest region.
Grubsong at 10 Grubs, 
Grubberfly's Elegy at 46.
Dream Nail every jar; real Grubs say "Home," Mimics say "Kill" or "Empty."Grubs are passive creatures stuck in glass jars. Per the wiki, "they can be freed by breaking the jar with the Nail, after which the Grub burrows into the ground and returns to Grubfather." There is no escort, no carry, no timer; one Nail swing on the jar and the rescue completes itself.
According to the wiki, every Grub jar emits an audio cue when the Knight is in range. "When close enough to their location, a faint crying noise can be heard in their general direction. The Grubs talk in high-pitched babbles and cannot be listened to." The cry pings before the jar is visible, which is the canonical signal a room has a hidden pickup.
The wiki specifies that Grubfather in the Grubhome at the northwest Forgotten Crossroads 
pays out milestone rewards based on the total saved, "not which Grubs have been saved." Order does not matter; only the cumulative count triggers each tier.
Dream Nail every glass jar before swinging the Nail. Per the wiki, Grub Mimics are hidden in real-Grub jars and transform into a hostile enemy when freed. A Dream Nail read of "...Home..." confirms a real Grub; "Kill," "Empty," or "Other" flags a Mimic. In actual play, this 1-second check saves a Mask against a surprise mid-air enemy spawn.
The 46 Grubs are spread across 13 named regions plus one Hot Spring sub-area. Per the wiki, the region count lines up with Hallownest's named maps and includes both overworld zones (Forgotten Crossroads, Greenpath, City of Tears) and lategame areas (The Hive, Tower of Love, Kingdom's Edge).
| Region | Grubs | Notes |
|---|---|---|
| Forgotten Crossroads | 5 | Tutorial-tier; first 5 are easy |
| Greenpath | 4 | Includes the Grubsong jar at 10 total |
| Fungal Wastes | 2 | Mantis Claw required for one |
| City of Tears | 4 | One needs Desolate Dive, one needs Great Husk Sentry kill |
Crystal Peak  | 7 | Densest region; multiple Lantern-gated |
| Resting Grounds | 2 | Both need Dream Nail-adjacent access |
| Royal Waterways | 3 | Simple Key gate + Isma's Tear for swim sections |
| Howling Cliffs | 1 | Mothwing Cloak only |
| Kingdom's Edge | 4 | Includes Hive overlap and Colosseum-adjacent |
Deepnest  | 5 | Lantern + Crystal Heart for the deeper jars |
Ancient Basin  | 2 | One needs Desolate Dive |
| The Hive | 2 | Hive Knight area + Isma's Tear acid |
Tower of Love  | 3 | Love Key required; includes the Grubberfly's Elegy jar |
| Hot Spring (Hive) | 2 | Adjacent to The Hive entry |
According to the wiki, the densest region is Crystal Peak with seven jars, followed by Forgotten Crossroads and Deepnest at five each. The Tower of Love requires the Love Key 
and contains the 46th Grub jar paired with the Grubberfly's Elegy reward.
The wiki specifies that several Grubs sit behind specific ability gates: "Mothwing Cloak" for early long-jumps, "Mantis Claw" for wall climbs, "Monarch Wings" for double jumps, "Crystal Heart" for super dashes, "Desolate Dive" for breakable floors, and "Isma's Tear" for acid swimming. A first-pass Grub sweep is roughly 60% of the total; the rest fall on later ability-gated returns.
Grubfather pays out fixed milestone rewards as the rescue count climbs. Per the wiki, the reward ladder runs from low Geo at the first rescues to the Grubberfly's Elegy Charm at the full 46.
| Grubs returned | Reward | What it does |
|---|---|---|
| 1 | Geo (small) | Starter reward |
| 5 | Mask Shard  | One quarter of a new Mask |
| 10 | Grubsong Charm | SOUL per damage taken |
| 15 | Pale Ore  | One of six required for Pure Nail |
| 20 | Hallownest Seal | Lemm relic, 450 Geo on resale |
| 23 | Grubfriend achievement | Half-rescue milestone, 5G |
| 25 | King's Idol | Lemm relic, 800 Geo on resale |
| 31 | Charm Notch | Extra Charm slot |
| 38 | Pale Ore (2nd) | Second Pale Ore drop |
| 40 | Rancid Egg  | Trade currency for Confessor Jiji |
| 46 | Grubberfly's Elegy + Metamorphosis | Full-Mask Nail beam Charm, 15G |
According to the wiki, the two capstone Charms anchor the entire questline. Grubsong at 10 rescues is the canonical sustain Charm for any no-Lifeblood run; it grants SOUL when the Knight takes damage. Grubberfly's Elegy at 46 fires Nail beams while the Knight is at full Masks, which is the in-fiction reward for completing the full Grub hunt.
The wiki specifies that "rescuing 23 or more Grubs rewards the Grubfriend achievement," and "rescuing all 46 Grubs rewards the Metamorphosis achievement." Both are 112%-completion gates: skipping the Grub hunt blocks the two Charms and the two achievements.
Grub Mimics are the only hostile fakes inside the Grub hunt. Per the wiki, "it is possible to come across a Grub Mimic trapped in a glass jar that transforms and becomes hostile when freed." Visually, a Mimic jar looks identical to a real Grub jar in motion and sprite; the difference only shows up via Dream Nail .
According to the wiki, "the easiest way to check if it is an actual Grub is to Dream Nail them. Grubs always say '...Home...' but Grub Mimics say '...Kill...', '...Empty...' or '...Other...'." The dialogue is the single reliable tell. The Dream Nail reading is free and instant; in practice it adds about a second per jar.
The wiki notes that breaking a Mimic jar without the Dream Nail check spawns a Grub Mimic enemy at point-blank range. The fight itself is short, but the surprise positioning catches new players mid-air or mid-Focus and usually costs at least one Mask. After a few runs, the Dream Nail step becomes automatic before any jar swing.
The first 30 to 35 Grubs usually fall out of normal exploration. The last 10 to 15 do not, and the wiki specifies the mechanic that solves them: the Collector 
"hoards living Grubs in glass jars; defeating the Collector unlocks the Collector's Map." The map "shows the locations of unfreed Grubs on purchased Maps."
According to the wiki, the Collector is a Dream-realm boss in the Watcher's Spire above the City of Tears 
and the fight unlocks after the Soul Master's arena is cleared. The Collector's Map is automatic from that point onward; Cornifer-purchased maps populate with Grub pin markers, including the ones on the area-map pickup screen.
The wiki specifies that the Collector fight is the practical halfway point of the Grub hunt mechanically. In actual play, the first pass without the Collector's Map yields about 30 Grubs, and the second pass with the Map yields the rest. The mid-game Watcher Knights gate is the rate-limiting step, not the Grubs themselves.
The Grub hunt anchors the Collector fight, the Grubfather reward chain, and three of the game's 112% milestones. 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.