Felonius Gru or simply just "Gru", is the main protagonist within the Despicable Me franchise. He is voiced by Steve Carell.
Gru comes from a long lineage of Gru's. Although his hometown is unknown, in an interview with Ellen DeGeneres he claimed he was from Albuquerque, New Mexico. As a child he had always dreamed of going to the moon. He made a "prototype" rocket out of macaroni and an actual working prototype rocket. For most of his childhood he was neglected and ignored by his mother, and it is unknown if this is what inspired him to become a supervillain, or if the Gru family is a family of supervillains, although his mother showed no signs of being one. He has worked with Dr. Nefario, who builds gadgets and weapons for Gru, for some time and based on what Dr. Nefario said, they have been planning the moon heist for a long time.
Gru returns home from an unknown endeavor only to learn of the theft of the Pyramid of Giza from Dr. Nefario. With his pride badly wounded, Gru assembles his Minions in his underground lair. He recalls the successful thefts of the Times Square jumbo-tron, and the miniature Statue of Liberty and Eiffel Tower from Las Vegas. He then reveals his long-time planned, most epic heist; the theft of the Moon.
Gru heads to the Bank of Evil to obtain a loan from Mr. Perkins, the bank's owner. While Gru waits for his audience with Mr. Perkins, Vector, another villain, annoys the former by showboating and displaying his piranha gun. When Gru finally gets to face Mr. Perkins, he asks for funding to build the rocket which is necessary for his plan to steal the moon. Mr. Perkins refuses to give him a loan unless Gru presents the SR-6. Additionally, during the meeting, Gru finds out from Mr. Perkins that it was Vector who stole the Pyramid of Giza. As Gru leaves the bank, he freezes Vector's head with his freeze ray.
During a testing of the shrink ray in a facility in East Asia, Gru steals it and flies off on his ship. However Vector steals the shrink ray from Gru mid-flight. Gru tries to shoot Vector down with guns and then with missiles, but fails. Vector then blasts Gru's ship with the shrink ray as payback for the latter freezing his head. This causes the ship to shrink, forcing Gru and the Minions to ride the miniaturized ship home.
Gru attempts to retake the shrink ray from Vector's lair only to be thwarted by its defensive systems, and Vector's pet shark. Gru sees three girls, Margo, Edith, and Agnes, trying to sell Vector cookies, and Vector lets them in. Gru plans on using the girls to reobtain the shrink ray and contacts Dr. Nefario and tells him to build a bunch of Cookie Robots for the theft. Gru goes to Miss Hattie's Home for Girls, the orphanage Margo, Edith and Agnes are from, masquerading as a dentist and adopts them.
The following day, the girls convince Gru to drive them to dance class before going to Vector's lair to deliver the large quantity of cookies that Vector ordered. After the class, the cookie robots are delivered by the girls and activated. The robots break into Vector's vault by hacking open the vault's door, and weld a hole in the wall from the inside. Gru and two Minions enter through the opening and grab the shrink ray, but as they are leaving they are sealed in by the cookie robots. They escape through some air vents and out to the main entrance (without Vector noticing) and return to the car.
On the way home, Gru and the girls stop by an amusement park called Super Silly Fun Land, which Gru sees as a chance to abandon the girls. After being forced to ride the roller coaster with them and helping Agnes win a unicorn stuffed toy, he ends up having fun with Margo, Edith and Agnes.
At his home, he fine-tunes his plan to Mr. Perkins via a teleconference, but he is interrupted by the girls during his presentation. Perkins surprises Gru by again refusing him the loan—claiming that while he doesn't have a problem with the plan, he doesn't want Gru to do it and he still wants a younger villain to do it. Though Gru is ready to abandon his plan due to lack of funds, the girls and the Minions donate money, sell Gru's furniture, and salvage scrap metal from junkyards to keep the plan going.
While the rocket is being built, Gru has fun with the girls, having tea parties with them, allowing them to have a slumber party, telling them bedtime stories and cooking them various shaped pancakes. Dr. Nefario soon begins to see the girls as a distraction to Gru. Since the moon heist and an important ballet recital the girls fall on the same day, Gru wants to move the day of the heist. Dr. Nefario confronts Gru and tells him how he feels the girls are becoming "a major distraction" and tells him "they need to go, if you don't do something about it, then I will." He remains true to his word and contacts Miss Hattie and requests she take the girls back to the orphanage. Both Gru and the girls are heartbroken.
The following day, on May 26, and with a broken heart, Gru boards the rocket and flies off to the moon, but not before one of the minions puts the ticket Agnes gave him into his space suit's pocket, despite Gru giving it back to that minion and telling him he doesn't have time for the girls dance recital. Gru shrinks the moon and pockets it. When he sees the ticket Agnes gave him, he realizes he has time to catch the recital. However, it has ended by the time he arrives. On the seat that the girls reserved for him, Gru finds a note from Vector, who has kidnapped the girls, telling him to bring the moon.
After forcing Gru to hand over the moon, Vector goes back on the deal and keeps the girls as his captives. This enrages Gru, who storms Vector's lair, the latter's defenses proving useless. Vector flees in an escape pod with the girls inside. Gru chases after them, climbing the disguised Pyramid and hanging onto the exterior of the ship. He nearly falls to his death, but is rescued by Dr. Nefario in the ship that Vector shrank previously. Nefario reveals that the effects of the shrink ray are not permanent and the effect wears off at a rate proportional to its original mass (which he calls the "Nefario Principle"), to put it simply, the bigger the object, the faster it returns to normal after being shrunk by the Shrink Ray.
As Gru gives chase to Vector, the effects of the shrink ray on the Moon inside the pod begin to wear off, causing the Moon to grow and smash open the glass bubble holding the girls. Gru rescues them by securing Vector's ship using a rope with a grappling hook and tells them to jump and that he will catch them. Edith and Agnes jump, and while Margo is about to jump, Vector catches her, but the (rapidly-expanding) Moon wrecks Vector's controls, causing his ship to accelerate into space and carry the moon back into orbit. Margo falls off the ship so Gru jumps off to catch her. The Minions join hands to form a lifeline, saving Gru and Margo.
Gru re-adopts the girls and they settle down to live a happy life as a family. He tells them a bedtime story about a unicorn whose life was changed when he met three little kittens (his own life story). The girls give a special recital for the minions, His mother, who after years of neglecting her son, finally tells him she is proud of him. A Minion changes the music from Swan Lake to disco, and everyone present rushes on stage to dance. As everyone else continues to dance, Gru raises himself and the girls up on a platform onto the roof of his house, and they watch the moon fill the sky, now in its rightful place.