diff --git a/code/modules/surgery/organs/parasites.dm b/code/modules/surgery/organs/parasites.dm
index 253eb5e50d1..536ca7a4f37 100644
--- a/code/modules/surgery/organs/parasites.dm
+++ b/code/modules/surgery/organs/parasites.dm
@@ -47,65 +47,75 @@
 	name = "terror eggs"
 	icon = 'icons/effects/effects.dmi'
 	icon_state = "eggs"
-	var/current_cycle = 0
-	var/awaymission_infection = 0
-	var/alternate_ending = 0
+
+	var/cycle_num = 0 // # of on_life() cycles completed, never reset
+	var/egg_progress = 0 // # of on_life() cycles completed, unlike cycle_num this is reset on each hatch event
+	var/egg_progress_per_hatch = 90 // if egg_progress > this, chance to hatch and reset egg_progress
+	var/eggs_hatched = 0 // num of hatch events completed
+	var/eggs_max = 3 // max possible spiderlings you can get from a single infection if its left to run for a very long time
+	var/awaymission_checked = FALSE
+	var/awaymission_infection = FALSE // TRUE if infection occurred inside gateway
+	var/list/types_basic = list(/mob/living/simple_animal/hostile/poison/terror_spider/red, /mob/living/simple_animal/hostile/poison/terror_spider/gray, /mob/living/simple_animal/hostile/poison/terror_spider/green)
 
 /obj/item/organ/internal/body_egg/terror_eggs/on_life()
-	current_cycle += 1
+	// Safety first.
+	if(!owner)
+		return
+
+	// Parasite growth
+	cycle_num += 1
+	egg_progress += pick(0, 1, 2)
+	egg_progress += calc_variable_progress()
+
+	// Detect & stop people attempting to bring a gateway white spider infection back to the main station.
+	if(!awaymission_checked)
+		awaymission_checked = TRUE
+		if(is_away_level(owner.z))
+			awaymission_infection = TRUE
+	if(awaymission_infection)
+		if(!is_away_level(owner.z))
+			owner.gib()
+			qdel(src)
+			return
+
+	// Detect dying hosts, and try to keep them alive (so spiderlings can hatch) at the cost of some growth progress.
 	if(owner.health < -25)
 		to_chat(owner,"<span class='notice'>You feel a strange, blissful senstation.</span>")
 		owner.adjustBruteLoss(-5)
 		owner.adjustFireLoss(-5)
 		owner.adjustToxLoss(-5)
-		// the spider eggs secrete stimulants to keep their host alive until they hatch
-	switch(current_cycle)
-		if(1) // immediately
-			to_chat(owner,"<span class='danger'>Your wound hurts horribly! </span>")
-			if(is_away_level(owner.z))
-				awaymission_infection = 1
-		if(15) // 30s... enough time for the nerve agent to kick in, the pain to be blocked, and healing to begin
-			to_chat(owner,"<span class='notice'>The pain has faded, and stopped bleeding, though the skin around it has turned black.</span>")
-			owner.adjustBruteLoss(-10)
-		if(30) // 1m... the point where the venom uses and accellerates the healing process, to feed the eggs
-			to_chat(owner,"<span class='notice'>Your wound has completely sealed up, though the skin is still black. You feel significantly better.</span>")
-			owner.adjustBruteLoss(-20)
-		if(90) // 3m... where the eggs are developing, and the wound is turning into a hatching site, but invisibly
-			to_chat(owner,"<span class='notice'>The black flesh around your old spider bite wound has started to peel off.</span>")
-		if(100) // 3m20s... where the victim realizes something is wrong - this is not a normal wound
-			to_chat(owner,"<span class='danger'>The black flesh around your spider bite wound has cracked, and started to split open!</span>")
-		if(110) // 3m40s...
-			to_chat(owner,"<span class='danger'>The black flesh splits open completely, revealing a cluster of small black oval shapes inside you, shapes that seem to be moving!</span>")
-		if(120) // 4m...
-			if(awaymission_infection && !is_away_level(owner.z))
-				// we started in the awaymission, we ended on the station.
-				// To prevent someone bringing an infection back, we're going to trigger an alternate, equally-bad result here.
-				// Actually, let's make it slightly worse... just to discourage people from bringing back infections.
-				alternate_ending = 1
-			to_chat(owner,"<span class='danger'>The shapes extend tendrils out of your wound... no... those are legs! SPIDER LEGS! You have spiderlings growing inside you! You scratch at the wound, but it just aggrivates them - they swarm out of the wound, biting you all over!</span>")
-			owner.visible_message("<span class='danger'>[owner] flails around on the floor as spiderlings erupt from [owner.p_their()] skin and swarm all over them! </span>")
-			owner.Stun(20)
-			owner.Weaken(20)
-			// yes, this is a long stun - that's intentional. Gotta give the spiderlings time to escape.
-			if(alternate_ending)
-				owner.gib()
-			else
-				owner.adjustToxLoss(rand(100,180)) // normal case, range: 100-180, average 140, almost crit (150).
-				if(prob(50))
-					var/obj/structure/spider/spiderling/terror_spiderling/S1 = new(get_turf(owner))
-					S1.grow_as = /mob/living/simple_animal/hostile/poison/terror_spider/red
-					S1.name = "red spiderling"
-				if(prob(50))
-					var/obj/structure/spider/spiderling/terror_spiderling/S2 = new(get_turf(owner))
-					S2.grow_as = /mob/living/simple_animal/hostile/poison/terror_spider/gray
-					S2.name = "gray spiderling"
-				if(prob(50))
-					var/obj/structure/spider/spiderling/terror_spiderling/S3 = new(get_turf(owner))
-					S3.grow_as = /mob/living/simple_animal/hostile/poison/terror_spider/green
-					S3.name = "green spiderling"
-		if(130) // 4m 20s
-			to_chat(owner,"<span class='danger'>The spiderlings are gone. Your wound, though, looks worse than ever. Remnants of tiny spider eggs, and dead spiders, inside your flesh. Disgusting.</span>")
-			qdel(src)
+		egg_progress += 10
+
+	// Once at least one egg has hatched from you, you'll need help to reach medbay.
+	if(eggs_hatched >= 1)
+		owner.Confused(2)
+
+	if(egg_progress > egg_progress_per_hatch && eggs_hatched < eggs_max)
+		egg_progress -= egg_progress_per_hatch
+		hatch_egg()
+
+/obj/item/organ/internal/body_egg/terror_eggs/proc/calc_variable_progress()
+	var/extra_progress = 0
+	if(owner.nutrition > NUTRITION_LEVEL_FULL)
+		extra_progress += 1
+	var/antibiotics = owner.reagents.get_reagent_amount("spaceacillin")
+	if(antibiotics > 50)
+		extra_progress -= 0.5
+	var/boosters = owner.reagents.get_reagent_amount("salglu_solution")
+	if(boosters > 1)
+		extra_progress += 1
+	return extra_progress
+
+/obj/item/organ/internal/body_egg/terror_eggs/proc/hatch_egg()
+	var/obj/structure/spider/spiderling/terror_spiderling/S = new(get_turf(owner))
+	if(eggs_hatched >= 2) // on the third egg...
+		S.grow_as = /mob/living/simple_animal/hostile/poison/terror_spider/princess
+	else
+		S.grow_as = pick(types_basic)
+	S.immediate_ventcrawl = TRUE
+	eggs_hatched++
+	to_chat(owner, "<span class='warning'>A strange prickling sensation moves across your skin... then suddenly the whole world seems to spin around you!</span>")
+	owner.Paralyse(10)
 
 /obj/item/organ/internal/body_egg/terror_eggs/remove(var/mob/living/carbon/M, var/special = 0)
 	..()