Lucky Emblems in Kingdom hearts 3 are "objects" that resemble Mickey Mouse's well known face&ears symbol. There are a total of 90 and are needed to unlock the Secret Ending, we need all the 90 Emblems in Beginner mode, 60 in Standard and 30 in Proud Mode in order to unlock it.

There are 11 Emblems in Monstropolis:

1- Start from Lobby & Offices Save Point and proceed to reach the Laugh Floor, once inside the room you'll see a Clown to your right, hit him to move him away the Emblem is under him.


2- Now reach the 7th desk on the left to see a note with a Lucky Emblem on it.



3- From the Door Vault Upper Level Save Point go past the elevator and you'll see the Emblem on the wall at the end of the path.



4- From the Factory Basement Save Point go past the door to your right, go all the way to the wall with all the doors on it and enter the farthest left one. Turn left to where the Fantastic is and you'll see the Emblem made of doors on the distant wall.



5- From the Factory Basement Save Point and make your way through the factory until you reach a corridor with some stairs, after the first set of stairs you'll see the emblem to your right.


6- From The Factory Ground Floor Save point move close to the paint containers, you'll spot the Emblem painted on the ground.


7- From the previous one take the lift and proceed through the Factory until you reach the South-East of the map, you'll find the Emblem up on the wall.


8- From The Power Plant Accessway Save Point, check the side of the locker behind Sully, the Emblem is on the right.


9- From the previous Emblem proceed to reach the South-West of the map, the Emblem is on top a door.


10- From the Tank Yard Save point climb your way on the North-East platform and turn yourself, you'll some Pipes with the shape of the Emblem.


11- From the Service Area Save Point  go back nd enter the Power Plant map, go on top of the small bridge and look down to spot the Emblem on the ground.


For a detailed walkthrough check the video below: