A bee as large as your thumb?
Megachile pluto - Wallace's Giant Bee
A5 size, pigment liner, coloured pencil, ink. From the Flickr page of C.Nahaboo
National Geographic: "The world largest bee (Megachile pluto) may also be the planet’s most elusive. First discovered in 1859 by the prominent scientist Alfred Russel Wallace, it was presumed extinct. In 1981, an entomologist named Adam Messer searched and found it on three islands in Indonesia, on an archipelago called the North Moluccas. He collected a specimen and wrote about his discovery in 1984". Read more HERE.