Grunt with toys

From Halopedia, the Halo wiki

The Grunt with toys is an Easter egg that is encountered in Halo 2 and Halo 2: Anniversary.

During the opening cinematic of Delta Halo, a Grunt can be seen playing with different toys, depending on the difficulty. On Easy, he plays with a stick and dirt, on Normal with plasma grenades, on Heroic with fire, and on Legendary with Master Chief and Grunt dolls in his hands. The objects disappear shortly before the UNSC SOEIVs' landing on the surface of Delta Halo.

In the Blur cinematic of Halo 2: Anniversary, the Grunt will have toys on all difficulties. This time, a Jackal is dangling a doll above the Grunt, who is batting at it until they are distracted by the SOEIVs. The dolls will change depending on the difficulty, with any dolls shown on lower difficulties accumulating on the log to the right of the scene. On Easy the doll is the Ur-Didact, on Normal the Librarian, on Heroic John-117, and on Legendary Rampant Cortana.