I made a vid of a well known glitch in halo:combat evolved where the flood follow you around but dont kill you.
how to do the glitch:
-kill the flood apart from one or two that arent carrying guns, this way you can do the next step more easily
-shoot the arm off the flood that hits you (best done with a pistol)
-thats it, simple! now the flood will follow you around
just as a side note: no i'm not really that sad in reality, its a video xD