mods/ENTITIES/mcl_mobs/api.lua

@@ -3467,7 +3467,10 @@ local mob_activate = function(self, staticdata, def, dtime)
 			def.textures = {def.textures}
 		end
 
-		self.base_texture = def.textures[random(1, #def.textures)]
+		local c = 1
+		if #def.textures > c then c = #def.textures end
+
+		self.base_texture = def.textures[math.random(c)]
 		self.base_mesh = def.mesh
 		self.base_size = self.visual_size
 		self.base_colbox = self.collisionbox

mods/ENTITIES/mobs_mc/tropical_fish.lua

@@ -72,7 +72,7 @@ local tropical_fish = {
 	collisionbox = {-0.2, 0.0, -0.2, 0.2, 0.1, 0.2},
 	visual = "mesh",
 	mesh = "extra_mobs_tropical_fish_a.b3d",
-	textures = {}, -- to be populated on_spawn
+	textures = { "extra_mobs_tropical_fish_a.png" }, -- to be populated on_spawn
 	sounds = {},
 	animation = {
 		stand_start = 0,