When the player kills the patrol leader in the creative mode, it will give Bad Omen effect.
Linked issues
relates to 4
MC-205069
Powdered snow doesn't give you frozen effect in creative mode
Resolved
MC-126085
Pufferfish attack invisible players and creative/spectator players
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MC-137456
Wither rose withers creative mode players
Resolved
MC-138675
Wither skulls inflict the Wither effect on players in Creative mode
Resolved
I think this is WAI. Presumably, for players who don't know how to use commands, they could search for an illager patrol leader and kill it, so that they could mess around with bad omen raids.