What is the name of the grumpy old man in Up?

The grumpy old man in Up is Carl Fredricksen.

Carl Fredricksen is the protagonist of Pixar’s 2009 film Up. He is a retired balloon salesman who lives in the house he once shared with his wife, Ellie. After Ellie’s death and pressure from developers to leave his neighborhood, Carl attaches thousands of balloons to the house and lifts it into the sky.

Carl intends to reach Paradise Falls in South America, a destination he and Ellie dreamed about visiting. His plan changes when he discovers Russell, an earnest young Wilderness Explorer, accidentally aboard the floating house. Their journey introduces them to Dug, a talking collar-equipped dog, and to Charles Muntz, Carl’s former childhood hero turned adversary.

Carl’s gruff personality reflects his grief and resistance to change, but the adventure gradually helps him reconnect with other people. Viewers sometimes confuse him with Russell, the boy who accompanies him, or Charles Muntz, the film’s antagonist. Carl was voiced by Ed Asner, whose distinctive delivery helped define the character’s warmth beneath his stern exterior.