Mr. Wong became the new school principal around the same time that Mrs. Hardesty arrived. Unlike Mrs. Hardesty, who is tough on Michael Munroe and his friends, he is far nicer to them, even rewarding them with candy bars after they clean out Mrs. Hardesty's dumpster. Michael, DeWayne and Daisy take a liking to him. However, after sneaking into Mrs. Hardesty's house, they soon learn the truth. Mrs. Hardesty is actually an alien who has been taking care of the eggs of reptilian monsters in a scheme to take over Earth under the command of a Commander Xannx.
Michael is eventually turned into one of the reptilian egg monsters. With the help of Dewayne and Daisy, he manages to escape from Hardesty's house, but the aliens give chase. They arrive at Mr. Wong's only to find him asleep and sitting on an alien egg. He is revealed to be Commander Xannx. However, the egg hatches underneath him, causing him to fall inside. Hardesty and the aliens try to pull him out, but also fall into the alien yolk, which dissolves them all.
Mr. Wong is described as a short toad-like man who always wears pinstripe suits and white shirts. It is unclear if this is how he actually looks, or if it is an alien disguise.
Mr. Wong is described as being rather nice, especially to Michael, DeWayne and Daisy. He often comes to their defense and even treats them with candy bars for their hard work. The revelation of Mr. Wong being Commander Xannx makes it questionable if he was always nice or if it was just a cover, but we never see the extent of how evil he truly is due to his quick and sudden death.