diff --git a/code/__DEFINES/DNA.dm b/code/__DEFINES/DNA.dm
index f343ab8f7a6c..14f3c314471f 100644
--- a/code/__DEFINES/DNA.dm
+++ b/code/__DEFINES/DNA.dm
@@ -104,6 +104,7 @@
 #define ORGAN_SLOT_LEFT_ARM_AUG "l_arm_device" //This one ignores alphabetical order cause the arms should be together
 #define ORGAN_SLOT_STOMACH "stomach"
 #define ORGAN_SLOT_STOMACH_AID "stomach_aid"
+#define ORGAN_SLOT_STORAGE_CAVITY "storage_cavity" // monkestation edit
 #define ORGAN_SLOT_THRUSTERS "thrusters"
 #define ORGAN_SLOT_TONGUE "tongue"
 #define ORGAN_SLOT_VOICE "vocal_cords"
diff --git a/monkestation/code/modules/antagonists/changeling/powers/storage_cavity.dm b/monkestation/code/modules/antagonists/changeling/powers/storage_cavity.dm
new file mode 100644
index 000000000000..190b8d96711b
--- /dev/null
+++ b/monkestation/code/modules/antagonists/changeling/powers/storage_cavity.dm
@@ -0,0 +1,188 @@
+/datum/action/changeling/storage_cavity
+	name = "Storage Cavity"
+	desc = "We evolve smaller organs, allowing us to covertly store things in their place. Opening and closing it isn't very stealthy, though."
+	helptext = "Can store up to 3 small items. IDs can open things from inside. Works in lesser form and while downed. Can be seen and removed via surgery."
+	button_icon = 'monkestation/icons/mob/actions/actions_changeling.dmi'
+	button_icon_state = "storage_cavity"
+	dna_cost = 1
+	req_stat = SOFT_CRIT
+
+	var/obj/item/organ/internal/storage_cavity/cavity
+
+/datum/action/changeling/storage_cavity/Grant(mob/grant_to)
+	. = ..()
+	create_cavity()
+
+/datum/action/changeling/storage_cavity/Remove(mob/remove_from)
+	. = ..()
+	qdel(cavity)
+
+/datum/action/changeling/storage_cavity/sting_action(mob/living/user, mob/living/target)
+	..()
+
+	if(create_cavity())
+		to_chat(user, span_warning("Our insides squelch as we regrow our storage cavity."))
+
+	if(!cavity)
+		user.balloon_alert(user, "no cavity!")
+		return FALSE
+
+	if(!cavity.atom_storage)
+		qdel(cavity) // Attempt to recover.
+		CRASH("[user] ([user.key]) tried to use their cavity storage, but it didn't have a storage datum. This should never happen.")
+
+	if(user in cavity.atom_storage.is_using)
+		cavity.atom_storage.hide_contents(user)
+	else
+		cavity.atom_storage.open_storage(user)
+
+	return FALSE
+
+/// Creates a storage cavity organ if we don't already have one. Returns whether we grew a new one.
+/datum/action/changeling/storage_cavity/proc/create_cavity()
+	if(!iscarbon(owner) || cavity)
+		return FALSE
+	cavity = new
+	cavity.Insert(owner)
+	RegisterSignals(cavity, list(COMSIG_QDELETING, COMSIG_ORGAN_REMOVED), PROC_REF(forget_cavity))
+	return TRUE
+
+/datum/action/changeling/storage_cavity/proc/forget_cavity(datum/source)
+	SIGNAL_HANDLER
+	UnregisterSignal(cavity, list(COMSIG_QDELETING, COMSIG_ORGAN_REMOVED))
+	cavity = null
+
+/obj/item/organ/internal/storage_cavity
+	name = "rigid membrane"
+	desc = "An enlarged protective membrane with rigid walls. It looks like a few things might fit inside."
+	icon = 'monkestation/icons/obj/medical/organs/organs.dmi'
+	icon_state = "storage_cavity"
+	visual = TRUE
+	zone = BODY_ZONE_CHEST
+	slot = ORGAN_SLOT_STORAGE_CAVITY
+	decay_factor = 0
+
+	var/list/access = list()
+
+/obj/item/organ/internal/storage_cavity/Initialize(mapload)
+	. = ..()
+	create_storage(storage_type = /datum/storage/storage_cavity)
+
+/obj/item/organ/internal/storage_cavity/Insert(mob/living/carbon/receiver, special, drop_if_replaced)
+	. = ..()
+	if(!. || !owner)
+		return
+	forceMove(receiver)
+	RegisterSignal(receiver, COMSIG_MOB_TRIED_ACCESS, PROC_REF(on_try_access))
+
+/obj/item/organ/internal/storage_cavity/Remove(mob/living/carbon/organ_owner, special)
+	. = ..()
+	UnregisterSignal(organ_owner, COMSIG_MOB_TRIED_ACCESS)
+
+/obj/item/organ/internal/storage_cavity/Entered(atom/movable/arrived, atom/old_loc, list/atom/old_locs)
+	. = ..()
+	if(isidcard(arrived))
+		var/obj/item/item = arrived
+		access += item.GetAccess()
+
+
+/obj/item/organ/internal/storage_cavity/Exited(atom/movable/gone, direction)
+	. = ..()
+	if(isidcard(gone))
+		var/obj/item/item = gone
+		access -= item.GetAccess()
+
+/obj/item/organ/internal/storage_cavity/proc/on_try_access(datum/source, obj/target)
+	SIGNAL_HANDLER
+	return target.check_access_list(access)
+
+/datum/storage/storage_cavity
+	max_specific_storage = WEIGHT_CLASS_SMALL
+	max_total_storage = 6
+	max_slots = 3
+	silent = TRUE
+	silent_for_user = TRUE
+	rustle_sound = FALSE
+	allow_big_nesting = FALSE
+
+	var/datum/bodypart_overlay/simple/storage_cavity/overlay
+
+	/// Hack to make refresh_views not trigger opening and closing effects.
+	var/refreshing
+
+/datum/storage/storage_cavity/open_storage(mob/user)
+	. = ..()
+	if(!. || refreshing)
+		return
+
+	var/obj/item/organ/cavity = real_location?.resolve()
+	if(!istype(cavity))
+		return
+
+	playsound(cavity, 'sound/effects/wounds/splatter.ogg', vol = 30, vary = TRUE, extrarange = SILENCED_SOUND_EXTRARANGE, ignore_walls = FALSE)
+
+	if(cavity.owner != user)
+		return
+
+	user.visible_message(
+		message = span_danger("[user]'s chest opens up, revealing a large cavity!"),
+		self_message = span_notice("We open our storage cavity."),
+		blind_message = span_hear("You hear a squelch."),
+		vision_distance = 2
+	)
+
+	apply_overlay(cavity, user)
+
+/datum/storage/storage_cavity/hide_contents(mob/user)
+	. = ..()
+	if(isobserver(user) || refreshing)
+		return
+
+	var/obj/item/organ/cavity = real_location?.resolve()
+	if(!istype(cavity))
+		return
+
+	playsound(cavity, 'sound/effects/wounds/splatter.ogg', vol = 30, vary = TRUE, extrarange = SILENCED_SOUND_EXTRARANGE, ignore_walls = FALSE)
+
+	if(cavity.owner != user)
+		return
+
+	user.visible_message(
+		message = span_danger("[user]'s chest closes up!"),
+		self_message = span_notice("We close our storage cavity."),
+		blind_message = span_hear("You hear a squelch."),
+		vision_distance = 2
+	)
+
+	clear_overlay(cavity, user)
+
+/datum/storage/storage_cavity/refresh_views()
+	refreshing = TRUE
+	. = ..()
+	refreshing = FALSE
+
+/datum/storage/storage_cavity/proc/apply_overlay(obj/item/organ/cavity, mob/living/carbon/user)
+	RegisterSignal(cavity, COMSIG_ORGAN_REMOVED, PROC_REF(clear_overlay))
+	RegisterSignal(user, COMSIG_ATOM_EXAMINE, PROC_REF(on_examine))
+	var/obj/item/bodypart/chest = user.get_bodypart(BODY_ZONE_CHEST)
+	overlay = new
+	chest.add_bodypart_overlay(overlay)
+	user.update_body()
+
+/datum/storage/storage_cavity/proc/clear_overlay(obj/item/organ/cavity, mob/living/carbon/user)
+	SIGNAL_HANDLER
+	UnregisterSignal(cavity, COMSIG_ORGAN_REMOVED)
+	UnregisterSignal(user, COMSIG_ATOM_EXAMINE)
+	var/obj/item/bodypart/chest = user.get_bodypart(BODY_ZONE_CHEST)
+	chest.remove_bodypart_overlay(overlay)
+	user.update_body()
+	QDEL_NULL(overlay)
+
+/datum/storage/storage_cavity/proc/on_examine(mob/living/carbon/user, mob/examiner, list/examine_text)
+	SIGNAL_HANDLER
+	examine_text += span_bolddanger("[user.p_Their()] chest has a large, open cavity!")
+
+/datum/bodypart_overlay/simple/storage_cavity
+	icon = 'monkestation/icons/mob/species/misc/bodypart_overlay_simple.dmi'
+	icon_state = "storage_cavity"
+	layers = EXTERNAL_ADJACENT
diff --git a/monkestation/icons/mob/actions/actions_changeling.dmi b/monkestation/icons/mob/actions/actions_changeling.dmi
new file mode 100644
index 000000000000..0977273d1c4f
Binary files /dev/null and b/monkestation/icons/mob/actions/actions_changeling.dmi differ
diff --git a/monkestation/icons/mob/species/misc/bodypart_overlay_simple.dmi b/monkestation/icons/mob/species/misc/bodypart_overlay_simple.dmi
new file mode 100644
index 000000000000..3b5ba7a08b96
Binary files /dev/null and b/monkestation/icons/mob/species/misc/bodypart_overlay_simple.dmi differ
diff --git a/monkestation/icons/obj/medical/organs/organs.dmi b/monkestation/icons/obj/medical/organs/organs.dmi
index ebe085756390..652c707805b9 100644
Binary files a/monkestation/icons/obj/medical/organs/organs.dmi and b/monkestation/icons/obj/medical/organs/organs.dmi differ
diff --git a/tgstation.dme b/tgstation.dme
index 8d632dee3037..e14aba6c89d9 100644
--- a/tgstation.dme
+++ b/tgstation.dme
@@ -6103,6 +6103,7 @@
 #include "monkestation\code\modules\antagonists\brother\gear\_gear.dm"
 #include "monkestation\code\modules\antagonists\brother\gear\misc.dm"
 #include "monkestation\code\modules\antagonists\brother\gear\recipes.dm"
+#include "monkestation\code\modules\antagonists\changeling\powers\storage_cavity.dm"
 #include "monkestation\code\modules\antagonists\changeling\powers\teratomas.dm"
 #include "monkestation\code\modules\antagonists\changeling\powers\tiny_prick.dm"
 #include "monkestation\code\modules\antagonists\clock_cult\area.dm"