Yersin, Hissing Miasma

Deathtouch

Whenever a nontoken creature you control dies,
you may have target opponent create a 1/1 Black
Rat creature token with " This creature can't be sacrificed.", and "At the beginning of your upkeep,
you lose 1 life."
{4}{b}: Target player loses X life where X is half
the number of tokens they control rounded down.