The Grunt with toys is an Unggoy that can be encountered in Halo 2.
During the opening cinematic of Delta Halo while playing on Legendary, partway in, a Unggoy can be seen sitting next to a Kig-Yar. If you look closely at him, it can be observed that the Unggoy has a John-117 figure in one hand and an Unggoy figure in the other. This Easter Egg is easier to observe if you take a picture and zoom in with an editing program. If you have Halo 2 Vista, you can use a screen capture program.