Freeze Ray

The freeze ray which was invented by Dr.Nefario, is Felonius Gru's signature weapon, when fired it projects a ray that freezes anything instantly.

Despicable Me
Gru is first seen utilizing the freeze ray to freeze everybody in a coffee shop, in order to bypass a line and get his coffee quickly. He later freezes Vector's head in jealous fit after finding out the latter is responsible for stealing the Pyramid of Giza. Edith and Agnes later used it on Gru while he is holding a teleconference with Mr. Perkins.

Despicable Me 2
When Anti-Villain League agent Lucy Wilde appears to escort Gru to the AVL's headquarters, he attempts to freeze her. She counters with a Flamethrower and proceeds to take him by force with a Lipstick Taser. Later Gru uses it to freeze Antonio, Margo's crush, after he broke her heart. In the final battle against the PX-41 mutated El Macho, Gru freezes his adversary's arms in an attempt to stall the giant villain. Unfortunately, he manages to break the ice while trying to attack Gru.

Minions
Gru presumably used it to freeze Scarlet Overkill and Herb. He later attempted to use it on the T-Rex in the credits, only for the freeze ray to jam.

Despicable Me 3
When Gru tried to steal the diamond from Balthazar Bratt, Gru points the Freeze ray at him and he knocks it to a side of the boat. Gru later used it to freeze the directors between him and Dru.

Appearance in Other Media
The Freeze Ray is a usable item in the game Minion Rush.

Trivia

 * This is one of the three weapons that appeared in both of the first two movies. The others are the Fart Gun and the Laser Gun.
 * The freeze ray is also currently the only weapon of Gru that appears in the four movies - Despicable Me, Despicable Me 2, Minions, and Despicable Me 3.