Slammers are a thick heavy pog used for throwing at other pogs. They are rarer, and cost more too. These have a foil background, which is common in slammers.
It seems every country had its own pogs. Australia's are cool though! They even had Metal Sonic. They used some clip art and symbols, but it seems they got a bit creative with the designs. For some reason, someone has set these on a drawing of some kind.