Grebs is a minor character from Antz. He is a drunk ant scout and is voiced by John Mahoney.
When Z is in the worker bar he complains that there has to be a better place to which the ant who is sitting next to him named Grebs, who is drunk, tells him that there is a better place and that he's been there and that it's called Insectopia where the streets are paved with foods and there's no wars and no colonies and he wishes that he never left.
Grebs then stands up and tells Z that to get to Insectopia he has to go to the monolith and 10 clicks pass the great cannon to the land of red and white to which another soldier ant comes up to Grebs and tells him that he's had enough aphid beer for one night and drags him out of the bar as Grebs continuously drunkly tells Z how to get to Insectopia as he's dragged out such as cross the lake and look for the land of red and white.
According to the Directors on the Audio Commentary for the film the Animators at Dreamworks designed Grebs to look like Cutter with whiskers but that the character is very different from Cutter and isn't Cutter.
John Mahoney voiced Grebs in the film while David Hyde Pierce who plays Mahoney's youngest son on Frasier voiced Slim the walking stick in the rival Pixar movie A Bug's Life.
It is unknown if Grebs had actually been to Insectopia before or if he was just making it up because he was drunk. However, the directions he gives Z prove to be helpful in finding it.