Decompose / Repose

Decompose

You reach out and touch a corpse or other remains of a creature. Almost immediately, the corpse begins to rapidly decompose, sprouting fungus and moss as it begins to decay. Odd-coloured flowers may also begin to spring forth.

Restoration or resurrection of the remains becomes impossible for the duration, but the remains may be reanimated as undead 24 hours after the spell is cast.

With this spell known or prepared, as a Reaction when a plant or undead creature moves within 10 feet of you, you may make a ranged spell attack to cast Chill Touch on the creature as a cantrip, without expending a spell slot. (If the target is immune to necrotic damage, then the damage is instead radiant.) This effect can not be repeated within 5 minutes.

Repose

You touch a corpse or other remains. For the duration, the target is protected from decay and can’t become undead.

The spell also effectively extends the time limit on raising the target from the dead, since days spent under the influence of this spell don’t count against the time limit of spells such as raise dead.

 Credit to Matt Mercer for the original Decompose cantrip.