give spiders unique venom reagent (#29066)

* add mechanotoxin

* make tarantulas use mechanotoxin

* trolled

---------

Co-authored-by: deltanedas <@deltanedas:kde.org>

Resources/Locale/en-US/reagents/meta/toxins.ftl

@@ -78,3 +78,6 @@ reagent-desc-tazinide = A highly dangerous metallic mixture which can interfere
 
 reagent-name-lipolicide = lipolicide
 reagent-desc-lipolicide = A powerful toxin that will destroy fat cells, massively reducing body weight in a short time. Deadly to those without nutriment in their body.
+
+reagent-name-mechanotoxin = mechanotoxin
+reagent-desc-mechanotoxin = A neurotoxin used as venom by some species of spider. Degrades movement when built up.

Resources/Prototypes/Entities/Mobs/NPCs/animals.yml

@@ -2229,7 +2229,7 @@
     solution: melee
     generated:
       reagents:
-      - ReagentId: Toxin
+      - ReagentId: Mechanotoxin
         Quantity: 1
   - type: MeleeChemicalInjector
     transferAmount: 0.75

Resources/Prototypes/Reagents/toxins.yml

@@ -662,3 +662,46 @@
             Poison: 2
       - !type:SatiateHunger
         factor: -6
+
+# inspired by the spider neurotoxin GsMtx-4
+# poisons non-spiders and slows you down at high doses
+- type: reagent
+  id: Mechanotoxin
+  name: reagent-name-mechanotoxin
+  group: Toxins
+  desc: reagent-desc-mechanotoxin
+  flavor: sweet
+  color: "#00b408"
+  physicalDesc: reagent-physical-desc-nondescript
+  metabolisms:
+    Poison:
+      metabolismRate: 0.2 # Slower metabolism so it can build up over time for slowdown
+      effects:
+      - !type:HealthChange
+        conditions:
+        - !type:OrganType
+          type: Arachnid
+          shouldHave: false
+        damage:
+          types:
+            Poison: 1.6
+      - !type:MovespeedModifier
+        conditions:
+        - !type:ReagentThreshold
+          reagent: Mechanotoxin
+          min: 2
+        - !type:OrganType
+          type: Arachnid
+          shouldHave: false
+        walkSpeedModifier: 0.8
+        sprintSpeedModifier: 0.8
+      - !type:MovespeedModifier
+        conditions:
+        - !type:ReagentThreshold
+          reagent: Mechanotoxin
+          min: 4
+        - !type:OrganType
+          type: Arachnid
+          shouldHave: false
+        walkSpeedModifier: 0.4
+        sprintSpeedModifier: 0.4