Goku Doll Parts
Mystic of Dragon Ball Online
All missions for Goku Doll are in City in Jungle (use Traveler).
There are 4 missions for 4 parts (screenshots).

First mission: Bring 25 saiyan tails to Miox for Goku Arm.
You can drop saiyan tails from Vegeta,Goku,Gohan,Bardock etc. (Saiyans)

Second mission: Bring 40 screws to John for Goku Head.
You can drop screws from Androids:Android Champion,Android Warrior,C16,C17,C18.

Third mission: Bring 15 piece of goku shirt for Goku Leg.
You can drop piece of goku shirt from: Goku (SSJ1,SSJ2,SSJ3,SSJ4,SSJ5).

Fourth and last mission: Ben will ask for some money for food for Goku Hands.
You need to have 35 Gold.

Now you need to use machine to stitch parts for a Goku Doll.
Place with machine (number 5).

Now you need to use the machine.

Now you can enter Big Kamehameha Quest with Goku Doll.