if you are stuck in this Moshi Mission, here's a walkthrough to get through any difficult parts you're in.
Talk to Buster Bumblechops, and click on "Where is Baby Rox now?" and after Buster Bumblechops is done talking, you will go to the Growl Mansion, where Baby Rox is.
When you arrive at Growl Mansion, Simon Growl will appear. Click on him to talk. As you're talking to him, you must select "You're lying! I can hear her crying!" When you select it, he will say "Oh...hmmm...well she is a little blue, I suppose. But you MUST NOT talk to her! I mean..she's very tired!" After he is done talking, you must trick Simon Growl into leaving the mansion.
When you are at this point, your monster will say "So Simon! Did you hear...", then tap "That Cheryl Troll's mansion is way bigger than yours!" After tapping that choice, he will leave the mansion. At this point, click on the door. You will be in Baby Rox's dressing room.
When entering Baby Rox's dressing room, you will hear her crying. In order to make her happy, you need the following things (You can pick them up by clicking them, and they will be stored in your inventory):
When you drag those items to Baby Rox, your monster will say "She is still a little blue! Can we entertain her somehow? What's that above her head?" Click the mobile, and Baby Rox will stop crying. Baby Rox will be ready to talk to your monster.
When your monster is talking with Baby Rox, she will have dots in her speech bubble. You will have three choices:
"No voice eh? You can dance!"
"I'm sorry, I don't speak dot!"
"Oh yeah, I forgot you can't speak!"
If you select any one of them, your monster and Baby Rox will continue talking. After that, Baby Rox points to a photo that was taken from the Underground Disco. When you view the photo, you'll see something that looks like DJ Quack. Press the X when you want to stop viewing it. You will be able to pick it up by clicking it. It will be sent to your inventory.
After obtaining the photo, you will arrive at the Underground Disco. Go into your inventory and give the photo to Bubba the Bouncer at the entrance. He will say "Oh! Didn't realize that Baby Rox sent you. Let's talk." Click on him to speak with him. You will have two choices:
"Baby Rox's voice! I have to get it back!"
"Ummm...I don't remember."
Click the first one. You will continue talking until you see three choices:
"There's a strange looking paparazzo!"
"You're stealing her voice!"
"I don't know."
Tap the first choice, and your monster and Bubba will continue talking. After the chat, there will be a Robo-Quack heading to an evil door. After it reaches the door, a character named Bonkers begins talking. Click on him to talk.
After your monster and Bonkers stop talking, Bonkers begins to sing a chant to open a shortcut to where the Robo-Quacks are. Upon entering said shortcut, you will be blocked with a musical puzzle. If you click the wrong note, you will have to try again. The order goes as follows:
Green Purple (click those two until next few notes play)
Green Purple Red Blue (click those until last notes play)
Green Purple Red Blue Pink Yellow
You will notice that it's to the tune of The Moshi Dance. After you completed the puzzle, the door will open. Click on the door to go into the next room. You will be in the CLONC lab, where a Rox Smasher is located, and a Robo-Quack is watching it destroy the Rox, using Baby Rox's voice. After the Robo-Quack catches you, it will fly away. You will hear quacking coming from somewhere. A mini-game, called Zap-a-Quack, will be activated. You have to defeat all the Robo-Quacks before proceeding. After completing the mini-game, you will see "You zapped all the Robo-Quacks!"
Step 8 (Final Step):
You will see the Rox Smasher destroyed, and Holga is out of it. Click on Holga to speak with her. You will see these two choices:
"Who is behind this evil plan?"
"How did they steal Baby Rox's voice?"
Select the first one, then Holga will send you back to Baby Rox with her voice in Holga's memory card. Click on Holga to make her do her moves. Baby Rox will sing, then talk. Click on her to talk with Baby Rox. She will have her voice back, and she will want you to have Holga. Click on Holga and she will be added to your Moshling Zoo.