Ngoo has moved to the Saddlers on-loan until the end of the season.
The 21 year-old is a player of undoubted talent and ability who will add to Dean Smith's attacking options.
"Michael is a lad that I have been watching for a long time," said Smith. "He is the right calibre and profile to fit into what we are trying to do here.
"He's big, strong, athletic and can score goals. Technically he is very good and will improve what we have already got here.
"On top of all of that, he is also a good character and someone that I am looking forward to working with."