He is Minion of Bowser. He is kind of magikkoopa.

After beating bowser in Peach`s Castle grounds he say:

"I helped you save Mushroom Kingdoom; however, that doesn`t means we are not enemies"

He gives you Green Sunshine from Goomboss and Red one from Big Bully.

He never kill you himselve.

Ripped from Yoshi`s Island SMW 2.