I never really knew what a katydid was (as opposed to a grasshopper) until the other night. An easy-to-spot difference is the length of the antennae. Also, katydids are primarily nocturnal and grasshoppers are diurnal.
Insects in the family Tettigoniidae are commonly called katydids (especially in North America). More than 8,000 species are known. Many species exhibit mimicry and camouflage, commonly with shapes and colours similar to leaves.
The specimen we sketched is in the Neoconocephalus genus. Gotta love that cone head!