diff --git a/Signal/src/Models/OWSAvatarBuilder.h b/Signal/src/Models/OWSAvatarBuilder.h
index 6ec98ef70..1f5234432 100644
--- a/Signal/src/Models/OWSAvatarBuilder.h
+++ b/Signal/src/Models/OWSAvatarBuilder.h
@@ -14,6 +14,8 @@ NS_ASSUME_NONNULL_BEGIN
                         diameter:(NSUInteger)diameter
                  contactsManager:(OWSContactsManager *)contactsManager NS_SWIFT_NAME(buildImage(thread:diameter:contactsManager:));
 
++ (UIImage *)buildRandomAvatarWithDiameter:(NSUInteger)diameter;
+
 - (nullable UIImage *)buildSavedImage;
 - (UIImage *)buildDefaultImage;
 - (UIImage *)build;
diff --git a/Signal/src/Models/OWSAvatarBuilder.m b/Signal/src/Models/OWSAvatarBuilder.m
index 25026d4c1..143ddcec9 100644
--- a/Signal/src/Models/OWSAvatarBuilder.m
+++ b/Signal/src/Models/OWSAvatarBuilder.m
@@ -3,10 +3,12 @@
 //
 
 #import "OWSAvatarBuilder.h"
+#import "JSQMessagesAvatarImageFactory.h"
 #import "OWSContactAvatarBuilder.h"
 #import "OWSGroupAvatarBuilder.h"
 #import "TSContactThread.h"
 #import "TSGroupThread.h"
+#import "UIColor+OWS.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -27,6 +29,45 @@ NS_ASSUME_NONNULL_BEGIN
     return [avatarBuilder build];
 }
 
++ (UIImage *)buildRandomAvatarWithDiameter:(NSUInteger)diameter
+{
+    NSArray<NSString *> *eyes = @[ @":", @"=", @"8", @"B" ];
+    NSArray<NSString *> *mouths = @[ @"3", @")", @"(", @"|", @"\\", @"P", @"D", @"o" ];
+    // eyebrows are rare
+    NSArray<NSString *> *eyebrows = @[ @">", @"", @"", @"", @"" ];
+
+    NSString *randomEye = eyes[arc4random_uniform((uint32_t)eyes.count)];
+    NSString *randomMouth = mouths[arc4random_uniform((uint32_t)mouths.count)];
+    NSString *randomEyebrow = eyebrows[arc4random_uniform((uint32_t)eyebrows.count)];
+    NSString *face = [NSString stringWithFormat:@"%@%@%@", randomEyebrow, randomEye, randomMouth];
+
+    CGFloat fontSize = (CGFloat)(diameter / 2.4);
+
+    UIImage *srcImage =
+        [[JSQMessagesAvatarImageFactory avatarImageWithUserInitials:face
+                                                    backgroundColor:[UIColor colorWithRGBHex:0xaca6633]
+                                                          textColor:[UIColor whiteColor]
+                                                               font:[UIFont boldSystemFontOfSize:fontSize]
+                                                           diameter:diameter] avatarImage];
+
+    UIGraphicsBeginImageContext(srcImage.size);
+
+    CGContextRef context = UIGraphicsGetCurrentContext();
+
+    CGFloat width = srcImage.size.width;
+
+    // Rotate
+    CGContextTranslateCTM(context, width / 2, width / 2);
+    CGContextRotateCTM(context, (CGFloat)M_PI_2);
+    CGContextTranslateCTM(context, -width / 2, -width / 2);
+
+    [srcImage drawAtPoint:CGPointMake(0, 0)];
+
+    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
+    UIGraphicsEndImageContext();
+    return image;
+}
+
 - (UIImage *)build
 {
     UIImage *_Nullable savedImage = [self buildSavedImage];
diff --git a/Signal/src/ViewControllers/DebugUI/DebugUIContacts.m b/Signal/src/ViewControllers/DebugUI/DebugUIContacts.m
index 665cfeeef..0f0bdff24 100644
--- a/Signal/src/ViewControllers/DebugUI/DebugUIContacts.m
+++ b/Signal/src/ViewControllers/DebugUI/DebugUIContacts.m
@@ -1134,7 +1134,7 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
-+ (void)createRandomContacts:(int)count
++ (void)createRandomContacts:(NSUInteger)count
 {
     OWSAssert(count > 0);
     [self createRandomContacts:count contactHandler:nil];
@@ -1163,16 +1163,34 @@ NS_ASSUME_NONNULL_BEGIN
                      }
 
                      CNSaveRequest *request = [[CNSaveRequest alloc] init];
-                     for (int i = 0; i < count; i++) {
+                     for (NSUInteger i = 0; i < count; i++) {
                          CNMutableContact *contact = [[CNMutableContact alloc] init];
                          contact.familyName = [@"Rando-" stringByAppendingString:[self randomLastName]];
                          contact.givenName = [self randomFirstName];
 
+                         NSString *phoneString = [self randomPhoneNumber];
                          CNLabeledValue *homePhone = [CNLabeledValue
                              labeledValueWithLabel:CNLabelHome
-                                             value:[CNPhoneNumber phoneNumberWithStringValue:[self randomPhoneNumber]]];
+                                             value:[CNPhoneNumber phoneNumberWithStringValue:phoneString]];
                          contact.phoneNumbers = @[ homePhone ];
 
+                         // 50% chance of fake contact having an avatar
+                         const NSUInteger kPercentWithAvatar = 50;
+                         const NSUInteger kMinimumAvatarDiameter = 200;
+                         const NSUInteger kMaximumAvatarDiameter = 800;
+                         OWSAssert(kMaximumAvatarDiameter >= kMinimumAvatarDiameter);
+                         if (arc4random_uniform(100) < kPercentWithAvatar) {
+                             NSUInteger avatarDiameter
+                                 = arc4random_uniform(kMaximumAvatarDiameter - kMinimumAvatarDiameter)
+                                 + kMinimumAvatarDiameter;
+                             // Note this doesn't work on iOS9, since iOS9 doesn't generate the imageThumbnailData from
+                             // programmatically assigned imageData. We could make our own thumbnail in Contact.m, but
+                             // it's not worth it for the sake of debug UI.
+                             contact.imageData = UIImageJPEGRepresentation(
+                                 [OWSAvatarBuilder buildRandomAvatarWithDiameter:avatarDiameter], (CGFloat)0.9);
+                             DDLogDebug(@"avatar size: %lu bytes", (unsigned long)contact.imageData.length);
+                         }
+
                          [contacts addObject:contact];
                          [request addContact:contact toContainerWithIdentifier:nil];
                      }