The tarantula hawk is neither a tarantula nor a hawk. It’s a really scary Pepsis wasp. It can grow really large and has an extremely painful sting. From Wikipedia:
Commenting on his own experience, Justin O. Schmidt, entomologist and creator of the Schmidt Sting Pain Index, described the pain as "…immediate, excruciating pain that simply shuts down one's ability to do anything, except, perhaps, scream. Mental discipline simply does not work in these situations." In terms of scale, the wasp's sting is rated near the top of the Schmidt sting pain index, second only to that of the bullet ant, and is described by Schmidt as "blinding, fierce [and] shockingly electric".
The tarantula hawk is the official state insect of New Mexico. But they range all over, with around 250 species in South America alone. Redditor Gonolek found this wasp dead in the hotel he worked at in Brazil. You can put your hand up your screen with his to picture how big it is. I would hate to encounter a wasp that size alive.