Thanks for jogging my memory slippery. I reckon I was 10-years-old when I went into the pipes aka 'tunnels'.
You could walk in some pipes if you hunched over. Once we got as far as the famous 'sixes' where six big storm water pipes met in the one place. I remember there were plenty of rats at the sixes. It was a good distance from Cabramatta Creek. We only had candles and a box of matches. Bloody dangerous, I don't remember any of us checking the weather forecast.
On another day, I swear we saw 'something' up there. Me and I my two young mates were about 50 yards in and we saw two red shiny things about 10 feet in front of us... it was bloody dark with only candle light to guide us, so we weren't sure. We stopped, and focussed... they were the shape of eyes. Then... one of our candles went out! Next moment there are three boys running for their lives to get out of the tunnel. lol
Of course by the time we got home the 'eyes' got larger and the 'creature' got bigger... and we reckoned it was growling. Plus the candle didn't just go out - it had been blown out by some mysterious wind.
The discussion had a mixture of humour, terror and excitement.
We had plans to go back up with sharp sticks (spears) and a blow torch (to use as a flame thrower of course)... but we never went in again.
It was probably some poor lost puppy, or cat... or just the overactive imagination of kids. But we three young boys remained friends well into our adult years and still spoke about it with fond memories.