From the Super Mario Wiki
“Peek a boo! Who are you? Peek a bee! Can't find me!”
Inviso is a boss from Yoshi's Story. He is at the end of Stage 3-2: Tall Tower. Inviso's appearance is somewhat hidden, as he is invisible (minus the fact that the world reflects on him). Inviso attacks by turning invisible and trying to bump into Yoshi while summoning Peepers. Yoshi can defeat Inviso by hitting him with three eggs. Inviso seems obsessed with the game of Peek-a-Boo.
In Yoshi's Island DS, presumably multiple Invisos appear. In the Hector the Reflector boss battle, creatures named Invisighouls pick up furniture and possess them, then throw them at Yoshi causing him to lick or be hit by the furniture. Not only is the name similar, but even more enforcing, they are ghosts that do not appear and Hector seems to look like Inviso very much.