Comics
Their comic versions had the names of; Fatso, Fusso, and Lazo. Unlike the familiar comic version.
Stretch
The leader of the trio and the most brutal when it comes to scaring. While he is the cruelest he is also the most responsible (not considering Casper).
Stinkie
Stinkie is the “middle child” of the group, well-known for his hideous odors. He tends to be the funniest of the group.
Fatso
Easily recognized as the fattest ghost, Fatso has a soft spot for anything edible. He is not particularly cruel to other his lower intelligence makes him easy to manipulate into scaring.
Related?
It’s not clear that the Ghostly Trio are related to each other or to Casper. Some versions have Casper and the trio related but other media also claim that they are only close friends.