Doomed Traveler

When Doomed Traveler dies, create a 1/1 white Spirit creature token with flying.

Mortician Beetle

Whenever a player sacrifices a creature, you may put a +1/+1 counter on Mortician Beetle.

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

When this creature dies, create a 1/1 black and green Insect creature token with flying.

When Tukatongue Thallid dies, create a 1/1 green Saproling creature token.