Blooey is a brown Blooper. He was originally white but Luigi accidentally threw him into a volcano when they were battling a stone creature causing Blooey to turn a golden brown.
Blooey is shown to be full of anger after Luigi basically made him "edible." Blooey stated that the only reason why he is going with Luigi on his journey is to pay him back for burning him. He even states that he'll get back at Luigi even it takes him his entire life.