Today, in south-east Scotland, I saw a plane that looked a bit like a Hercules but had four pods on each wing. I'm pretty sure that three of them were propeller engines and the end one was something else. They all looked a similar size. Height was lowish but not very low and it did not show up on flightradar24. I could not discern colour. I didn't get much of a look as I rushed in to get binoculars and it was well past and banking to the right when I got out again.
You've probably seen a tanker variant of the C-130, like this KC-130J:
On each wing there is an extra fuel tank and the pod containing the air-refueling hose.