Yup it is indeed my mod! What Succubism said is true, you get that message whenever a zombie spawns in your world wearing your player head. It shouldn't occur more then every 15 minutes but if it gets annoying, it can be disabled in the config or you can adjust how often it occurs. It's mostly designed as a way for hardcore players or players who are trying to avoid death to get their own head. If you're interested about learning more about the mod in general, you can check out
http://kihirakreations.co.uk/mcmods/player-beacons/ which has details on most of the aspects of the mod (there is also a vague lore book that spawns in-game as well) and of course, you can always PM me to ask questions!
I should also point out that the current version in the pack, 1.1.1 doesn't have TC integration however when it's updated to 1.2.0, it will!