[mobs] Add egg recipes for 4 basic monsters

- Add egg recipes for dirt, sand, stone and tree monsters

mods/mobs/dirtmonster.lua

@@ -62,3 +62,12 @@ mobs:register_mob("mobs:dirt_monster", {
 mobs:spawn_specific("mobs:dirt_monster", {"default:dirt_with_grass", "default:dirt_with_dry_grass"}, {"air"}, -1, 5, 30, 10000, 1, -31000, 31000, false)
 -- register spawn egg
 mobs:register_egg("mobs:dirt_monster", "Dirt Monster", "mobs_dirt_monster_inv.png", 1)
+
+minetest.register_craft({
+	output = "mobs:dirt_monster",
+	recipe = {
+		{"default:dirt", "default:dirt", "default:dirt"},
+		{"default:dirt", "default:nyancat_rainbow", "default:dirt"},
+		{"default:dirt", "default:dirt", "default:dirt"}
+	}
+})

mods/mobs/sandmonster.lua

@@ -62,3 +62,12 @@ mobs:register_mob("mobs:sand_monster", {
 mobs:spawn_specific("mobs:sand_monster", {"default:desert_sand", "default:sand"}, {"air"}, -1, 20, 30, 20000, 1, -31000, 31000, false)
 -- register spawn egg
 mobs:register_egg("mobs:sand_monster", "Sand Monster", "mobs_sand_monster_inv.png", 1)
+
+minetest.register_craft({
+	output = "mobs:sand_monster",
+	recipe = {
+		{"group:sand", "group:sand", "group:sand"},
+		{"group:sand", "default:nyancat_rainbow", "group:sand"},
+		{"group:sand", "group:sand", "group:sand"}
+	}
+})

mods/mobs/stonemonster.lua

@@ -66,3 +66,12 @@ mobs:register_mob("mobs:stone_monster", {
 mobs:spawn_specific("mobs:stone_monster", {"default:stone", "default:sandstone"}, {"air"}, -1, 5, 30, 7000, 1, -31000, -25, false)
 -- register spawn egg
 mobs:register_egg("mobs:stone_monster", "Stone Monster", "mobs_stone_monster_inv.png", 1)
+
+minetest.register_craft({
+	output = "mobs:stone_monster",
+	recipe = {
+		{"default:stone", "default:stone", "default:stone"},
+		{"default:stone", "default:nyancat_rainbow", "default:stone"},
+		{"default:stone", "default:stone", "default:stone"}
+	}
+})

mods/mobs/treemonster.lua

@@ -72,4 +72,13 @@ mobs:register_egg("mobs:tree_monster", "Tree Monster", "mobs_tree_monster_inv.pn
 if not minetest.get_modpath("ethereal") then
 	minetest.register_alias("ethereal:tree_sapling", "default:sapling")
 	minetest.register_alias("ethereal:jungle_tree_sapling", "default:junglesapling")
-end
+end
+
+minetest.register_craft({
+	output = "mobs:tree_monster",
+	recipe = {
+		{"default:tree", "default:tree", "default:tree"},
+		{"default:tree", "default:nyancat_rainbow", "default:tree"},
+		{"default:tree", "default:tree", "default:tree"}
+	}
+})