Isn’t the English language wonderful in its ambiguity? It’s not the eggs that are carnivorous but the mollusc that laid these eggs. According to the good folks at the Queensland Museum, it’s a predatory marine snail and most likely to be one of the murex snail group (family Muricidae), possibly Lepsiella hanleyi or Morula marginalba (the mulberry whelk, photo further down), or even one of the cone snail family (Conidae), Conus papilliferus.
Here’s a shot showing real size.
I’ve seen those cone shells, and Morula marginalba is prolific on that rock platform.
The hermit crabs above are possibly Clibanarius virescens.
This website shows photos of a bunch of different mollusc egg masses.