Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Curse of the Pierced Heart

Enchant player
At the beginning of enchanted player's upkeep, Curse of the Pierced Heart deals 1 damage to that player or a planeswalker that player controls.

Chandra, Awakened Inferno

This spell can't be countered.
+2: Each opponent gets an emblem with "At the beginning of your upkeep, this emblem deals 1 damage to you."
−3: Chandra, Awakened Inferno deals 3 damage to each non-Elemental creature.
−X: Chandra, Awakened Inferno deals X damage to target creature or planeswalker. If a permanent dealt damage this way would die this turn, exile it instead.

Valgavoth, Harrower of Souls

Flying
Ward—Pay 2 life.
Whenever an opponent loses life for the first time during each of their turns, put a +1/+1 counter on Valgavoth, Harrower of Souls and draw a card.

Leeching Licid

{B}, {T}: Leeching Licid loses this ability and becomes an Aura enchantment with enchant creature. Attach it to target creature. You may pay {B} to end this effect.
At the beginning of the upkeep of enchanted creature's controller, Leeching Licid deals 1 damage to that player.

Chandra, Awakened Inferno Emblem

At the beginning of your upkeep, this emblem deals 1 damage to you.

Relic Robber

Haste
Whenever Relic Robber deals combat damage to a player, that player creates a 0/1 colorless Goblin Construct artifact creature token with "This creature can't block" and "At the beginning of your upkeep, this creature deals 1 damage to you."