diff --git a/src/main/java/com/garbagemule/MobArena/things/ThingGroupPicker.java b/src/main/java/com/garbagemule/MobArena/things/ThingGroupPicker.java
index 8506b1c..4266f0d 100644
--- a/src/main/java/com/garbagemule/MobArena/things/ThingGroupPicker.java
+++ b/src/main/java/com/garbagemule/MobArena/things/ThingGroupPicker.java
@@ -19,6 +19,14 @@ public class ThingGroupPicker implements ThingPicker {
             .filter(Objects::nonNull)
             .collect(Collectors.toList());
 
+        if (things.isEmpty()) {
+            return null;
+        }
+
+        if (things.size() == 1) {
+            return things.get(0);
+        }
+
         return new ThingGroup(things);
     }
 
diff --git a/src/test/java/com/garbagemule/MobArena/things/ThingGroupPickerTest.java b/src/test/java/com/garbagemule/MobArena/things/ThingGroupPickerTest.java
index ae1affb..56dc735 100644
--- a/src/test/java/com/garbagemule/MobArena/things/ThingGroupPickerTest.java
+++ b/src/test/java/com/garbagemule/MobArena/things/ThingGroupPickerTest.java
@@ -2,14 +2,17 @@ package com.garbagemule.MobArena.things;
 
 import org.junit.Before;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.junit.MockitoJUnitRunner;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
+import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.MatcherAssert.*;
+import static org.mockito.Mockito.*;
 
+@RunWith(MockitoJUnitRunner.StrictStubs.class)
 public class ThingGroupPickerTest {
 
     private ThingGroupPicker subject;
@@ -22,19 +25,71 @@ public class ThingGroupPickerTest {
     }
 
     @Test
-    public void invokesAllPickers() {
-        ThingPicker first = mock(ThingPicker.class);
-        ThingPicker second = mock(ThingPicker.class);
-        ThingPicker third = mock(ThingPicker.class);
-        pickers.add(first);
-        pickers.add(second);
-        pickers.add(third);
+    public void returnsNullIfResultIsEmpty() {
+        Thing result = subject.pick();
 
-        subject.pick();
+        assertThat(result, nullValue());
+    }
 
-        verify(first, times(1)).pick();
-        verify(second, times(1)).pick();
-        verify(third, times(1)).pick();
+    @Test
+    public void returnsSingletonItemIfResultSizeIsOne() {
+        Thing thing = mock(Thing.class);
+        ThingPicker picker = mock(ThingPicker.class);
+        when(picker.pick()).thenReturn(thing);
+        pickers.add(picker);
+
+        Thing result = subject.pick();
+
+        assertThat(result, sameInstance(thing));
+    }
+
+    @Test
+    public void returnsThingGroupIfResultSizeIsGreaterThanOne() {
+        Thing thing1 = mock(Thing.class);
+        Thing thing2 = mock(Thing.class);
+        ThingPicker picker1 = mock(ThingPicker.class);
+        ThingPicker picker2 = mock(ThingPicker.class);
+        when(picker1.pick()).thenReturn(thing1);
+        when(picker2.pick()).thenReturn(thing2);
+        pickers.add(picker1);
+        pickers.add(picker2);
+
+        Thing result = subject.pick();
+
+        assertThat(result, instanceOf(ThingGroup.class));
+    }
+
+    @Test
+    public void skipsNullPickInTwoPickersAndReturnsSingleton() {
+        // This test is kind of "cheating" in that we're building off
+        // the knowledge that a singleton result is returned as-is,
+        // but at the time of writing, there's no straightforward way
+        // to verify that nulls are omitted.
+        Thing thing2 = mock(Thing.class);
+        ThingPicker picker1 = mock(ThingPicker.class);
+        ThingPicker picker2 = mock(ThingPicker.class);
+        when(picker1.pick()).thenReturn(null);
+        when(picker2.pick()).thenReturn(thing2);
+        pickers.add(picker1);
+        pickers.add(picker2);
+
+        Thing result = subject.pick();
+
+        assertThat(result, sameInstance(thing2));
+    }
+
+    @Test
+    public void toStringConcatenatesWithAnd() {
+        ThingPicker picker1 = mock(ThingPicker.class);
+        ThingPicker picker2 = mock(ThingPicker.class);
+        when(picker1.toString()).thenReturn("p1");
+        when(picker2.toString()).thenReturn("p2");
+        pickers.add(picker1);
+        pickers.add(picker2);
+
+        String result = subject.toString();
+
+        assertThat(result, equalTo("(p1 and p2)"));
     }
 
 }