What published source contained antimagic oozes?

So, I was talking with a friend about how to disable divine casters in D&D 3.5e, and they raised an intriguing possibility in that an unfortunate encounter with something called an "antimagic ooze" could do the job. However, they weren’t able to provide a citation for it, just the following details:

  • It projects an antimagic field for a ~30′ radius about it
  • Touching it makes the toucher permanently lose their ability to cast spells
  • It apparently is an (epic-level) trap, not a creature?
  • They recall it being in a Dragon Magazine somewhere, possibly as a variation on the Flux Slime epic hazard published in the D&D 3.5e SRD

Where was this published (if anywhere)?