SWALKER - that's what the buggers looked like, one was a juvenile which are more aggressive than the adults. We have seen tiger snakes before and they generally just carry on about their business so long as you make lots of noise and do not try and catch them.
There are loads of them in and around Perth, especially in wet areas arouns lakes and rivers; apparently they quite like eating frogs.
There have been a number of fatal bitings in Perth as more land is cleared for housing developments, moving the wildlife out of their natural habitats and into closer proximity with humans. I'll have to get a harness and lead for our cats, they normally bring us birds and mice but I reckon they would give a snake a good run for it's money