have a cob on
To be angry, agitated, or irritated. Primarily heard in UK. John always has a cob on after getting stuck in traffic on his way to work. I don't know why you have a cob on—I was only trying to be helpful!
get a cob on
To become angry, agitated, or irritated. Primarily heard in UK. John always gets a cob on over the traffic on his way to work. Don't get a cob on—I was only trying to be helpful!