Strolling Stone: new monster

A craggy, mossy beast inhabiting the early dungeon. When it attacks it
will shed plant-based detritus in the form of toadstools and lichen.

A pre-Lair addition to D that requires careful handling and frustrates
the player by littering the battlefield with obstacles.

crawl-ref/source/dat/descript/monsters.txt

@@ -2883,6 +2883,12 @@ strange machine
 A strange mechanical contraption, all hisses and pops. Shadows seem to dance
 across its reflective surface.
 %%%%
+strolling stone
+
+They say a rolling stone gathers no moss; but a strolling one gathers all
+kinds of detritus. A craggy, statuesque beast, shuffling through the dungeon
+covered in moss, lichen, and mushrooms.
+%%%%
 sun demon
 
 A demonic figure shining with the heat and fury of a fallen star.

crawl-ref/source/dat/mons/strolling-stone.yaml

@@ -0,0 +1,18 @@
+name: "strolling stone"
+glyph: {char: "9", colour: lightgreen}
+flags: [speaks, no_skeleton]
+resists: {elec: 1, petrify: 1}
+genus: golem
+holiness: [nonliving]
+will: 20
+attacks:
+ - {type: hit, flavour: shed, damage: 13}
+hd: 5
+hp_10x: 290
+ac: 5
+ev: 2
+shout: moan
+intelligence: human
+speed: 10
+size: large
+shape: humanoid

crawl-ref/source/describe.cc

@@ -5170,6 +5170,7 @@ static string _flavour_base_desc(attack_flavour flavour)
         { AF_AIRSTRIKE,         "open air damage" },
         { AF_TRICKSTER,         "drain, daze, or confuse" },
         { AF_VEX,               "cause vexation" },
+        { AF_SHED,              "sheds detritus from its body" },
         { AF_PLAIN,             "" },
     };
 

crawl-ref/source/melee-attack.cc

@@ -3776,6 +3776,7 @@ void melee_attack::mons_apply_attack_flavour()
         }
         break;
     }
+
     case AF_SLEEP:
         if (!coinflip())
             break;
@@ -3794,7 +3795,6 @@ void melee_attack::mons_apply_attack_flavour()
         defender->put_to_sleep(attacker, random_range(3, 5) * BASELINE_DELAY);
         break;
 
-
     case AF_ALEMBIC:
     {
         if (needs_message)
@@ -3828,6 +3828,13 @@ void melee_attack::mons_apply_attack_flavour()
         if (--attacker->as_monster()->number == 0)
             alembic_brew_potion(*attacker->as_monster());
     }
+
+    case AF_SHED:
+    {
+        if (!defender->is_firewood())
+            summon_detritus(*attacker->as_monster(), defender->pos());
+        break;
+    }
     break;
 
     case AF_BOMBLET:

crawl-ref/source/mon-death.cc

@@ -3150,6 +3150,10 @@ item_def* monster_die(monster& mons, killer_type killer,
             bennu_revive_fineff::schedule(mons.pos(), revives, att, mons.foe,
                                           duel, gozag_bribe);
         }
+        // XX: if the strolling stone *was* an illusion/summoned, unsummon its
+        // illusory sheddings too...
+        else if (mons.type == MONS_STROLLING_STONE)
+            summon_detritus(mons, mons.pos(), true);
     }
 
     if (mons_is_tentacle_head(mons_base_type(mons)))

crawl-ref/source/mon-enum.h

@@ -157,6 +157,7 @@ enum attack_flavour
     AF_TRICKSTER,
     AF_SILVER,
     AF_VEX,
+    AF_SHED,
 };
 
 // Non-spell "summoning" types to give to monster::mark_summoned(), or

crawl-ref/source/mon-pick-data.h

@@ -114,6 +114,7 @@ static const vector<pop_entry> population[] =
   {  6,  9, 1000, PEAK, MONS_BULLFROG },
   {  6, 10,  500, PEAK, MONS_WIGHT },
   {  6, 10,  350, PEAK, MONS_STEAM_DRAGON },
+  {  6, 10,  200, PEAK, MONS_STROLLING_STONE},
   {  6, 11,  500, PEAK, MONS_KOBOLD_BRIGAND },
   {  6, 12,  600, PEAK, MONS_ORC_WARRIOR },
   {  7, 11,  500, PEAK, MONS_KILLER_BEE },

crawl-ref/source/mon-place.cc

@@ -1403,6 +1403,8 @@ static monster* _place_monster_aux(const mgen_data &mg, const monster *leader,
     }
     else if (mons_is_child_tentacle(mg.cls))
         blame_prefix = "attached to ";
+    else if (mg.cls == MONS_TOADSTOOL || mg.cls == MONS_WOLF_LICHEN)
+        blame_prefix = "shed by ";
     else
         blame_prefix = "created by ";
 

crawl-ref/source/monster-type.h

@@ -677,6 +677,7 @@ enum monster_type                      // env.mons[].type
     MONS_HELLFIRE_MORTAR,
     MONS_SPLINTERFROST_BARRICADE,
     MONS_SHADOW_TURRET,
+    MONS_STROLLING_STONE,
 #endif
 
     // Demons:
@@ -1341,6 +1342,7 @@ enum monster_type                      // env.mons[].type
     MONS_ROCK_FISH_SCHOOL,
     MONS_SILVER_FISH,
     MONS_WOLF_LICHEN,
+    MONS_STROLLING_STONE,
 #endif
 
     NUM_MONSTERS,               // used for polymorph

crawl-ref/source/rltiles/dc-mon.txt

@@ -643,6 +643,7 @@ gargoyle MONS_GARGOYLE
 war_gargoyle MONS_WAR_GARGOYLE
 molten_gargoyle MONS_MOLTEN_GARGOYLE
 %rim 0
+strolling_stone MONS_STROLLING_STONE
 nargun MONS_NARGUN
 %rim 1
 

crawl-ref/source/spl-summoning.cc

@@ -2706,6 +2706,89 @@ bool summon_swarm_clone(const monster& agent, coord_def target_pos)
     return false;
 }
 
+bool summon_detritus(const monster& agent, coord_def target_pos, bool is_death)
+{
+    // Apply pseudo-summon cap
+    int count_shroom = 0;
+    int count_lichen = 0;
+    for (monster_iterator mi; mi; ++mi)
+    {
+        if (mi->summoner == agent.mid)
+        {
+            if (mi->type == MONS_WOLF_LICHEN)
+                count_lichen++;
+            else if (mi->type == MONS_TOADSTOOL)
+                count_shroom++;
+        }
+    }
+
+    int num_shroom = 0;
+    int num_lichen = 0;
+    const int num_total = is_death ? 4 : 2;
+
+    // Create up to 4 max of each type
+    for (int n=0; n<num_total; n++)
+    {
+        const int choice = random_range(0, 2);
+        if (choice == 1 && num_shroom + count_shroom < 4)
+            num_shroom++;
+        else if (choice == 2 && num_lichen + count_lichen < 4)
+            num_lichen++;
+    }
+
+    int seen_shroom = 0;
+    int seen_lichen = 0;
+
+    if (num_shroom > 0)
+    {
+        for (int n=0; n<num_shroom; n++)
+        {
+            // XX: Maybe don't copy behaviour?
+            mgen_data mg(MONS_TOADSTOOL, BEH_COPY, target_pos,
+                         _auto_autofoe(&agent), MG_AUTOFOE);
+            mg.set_summoned(&agent, 0, SPELL_NO_SPELL, GOD_NO_GOD); // Fedhas?
+
+            if (monster* spawn = create_monster(mg))
+            {
+                if (you.can_see(agent) || you.can_see(*spawn))
+                    seen_shroom++;
+            }
+        }
+    }
+
+    if (num_lichen > 0)
+    {
+        for (int n=0; n<num_lichen; n++)
+        {
+            mgen_data mg(MONS_WOLF_LICHEN, BEH_COPY, target_pos,
+                         _auto_autofoe(&agent), MG_AUTOFOE);
+            mg.set_summoned(&agent, 0, SPELL_NO_SPELL, GOD_NO_GOD); // Fedhas?
+
+            if (monster* spawn = create_monster(mg))
+            {
+                if (you.can_see(agent) || you.can_see(*spawn))
+                    seen_lichen++;
+            }
+        }
+    }
+
+    if (!seen_shroom && !seen_lichen)
+        return false;
+
+    string seen_what = "";
+    if (seen_lichen)
+        seen_what += "lichen";
+    if (seen_lichen && seen_shroom)
+        seen_what += " and ";
+    if (seen_shroom)
+        seen_what += "toadstools";
+
+    mprf("%s sheds %s!", you.can_see(agent) ? agent.name(DESC_THE).c_str() : "Something",
+         seen_what.c_str());
+
+    return true;
+}
+
 bool summon_spider(const actor &agent, coord_def pos,
                         spell_type spell, int pow)
 {

crawl-ref/source/spl-summoning.h

@@ -131,6 +131,7 @@ bool summon_hell_out_of_bat(const actor &agent, coord_def pos);
 bool summon_spider(const actor &agent, coord_def pos, spell_type spell, int pow);
 spret summon_spiders(actor &agent, int pow, bool fail = false);
 bool summon_swarm_clone(const monster& agent, coord_def target_pos);
+bool summon_detritus(const monster& agent, coord_def target_pos, bool is_death = false);
 
 spret summon_butterflies();