Based on the creature by Trevor Henderson.
"Siren Head" will randomly spawn and hunt you down, so, don't die?
(every time a Zombie, Husk, or Creeper spawns on the surface there is a 1 in 40 chance of Siren Head spawning, does not work in mountain biomes)
Siren Head can be instantly summoned using the command:
/function siren_head_43615:summon
Siren Head stats:
Health - 250 (125 Hearts)
Attack Damage - 14 (7 Hearts without armor)
Follow Range - 14 (7 Hearts without armor)
Can Break Doors? - Yes
Makes obvious noise when spawned - Yes
Known Bugs:
Known Bugs are listed on the Planet Minecraft page. https://www.planetminecraft.com/data-pack/siren-head-datapack/