I'm experimenting with agro range with my chicks in IoD. If you agro one of my killer chickens, agro it and run away. The chicken will die.
1. .rift 1
2. .move -34563 -16306 1050
3. .setdev 0
4. Start running like hell SW back to town, cut left at the fork and run a short distance and turn around
5. Around -35704 -4031 242 the chicken will die, there will be a chicken corpse
6. Rinse/repeat if needed
Be quick when you turn around cause the corpse only lasts a few secs.
Note: There's really nothing special about my chickens other than I made some of them agro for testing. There are other agro mobs that you can use. This was just an easy path to look/test with.