Blightwidow

Reach (This creature can block creatures with flying.)
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Ikra Shidiqi, the Usurper

Menace
Whenever a creature you control deals combat damage to a player, you gain life equal to that creature's toughness.
Partner (You can have two commanders if both have partner.)

Willowdusk, Essence Seer

{1}, {T}: Choose another target creature. Put a number of +1/+1 counters on it equal to the amount of life you gained this turn or the amount of life you lost this turn, whichever is greater. Activate only as a sorcery.

Arasta of the Endless Web

Reach
Whenever an opponent casts an instant or sorcery spell, create a 1/2 green Spider creature token with reach.

Honor Troll

Vigilance
If you would gain life, you gain that much life plus 1 instead.
This creature gets +2/+1 as long as you have 25 or more life.

Golgari Signet

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Grim Feast

At the beginning of your upkeep, this enchantment deals 1 damage to you.
Whenever a creature is put into an opponent's graveyard from the battlefield, you gain life equal to its toughness.

Abzan Beastmaster

At the beginning of your upkeep, draw a card if you control the creature with the greatest toughness or tied for the greatest toughness.

Rotwidow Pack

Reach
{3}{B}{G}, Exile a creature card from your graveyard: Create a 1/2 green Spider creature token with reach, then each opponent loses 1 life for each Spider you control.

Ishkanah, Grafwidow

Reach
Delirium — When Ishkanah enters, if there are four or more card types among cards in your graveyard, create three 1/2 green Spider creature tokens with reach.
{6}{B}: Target opponent loses 1 life for each Spider you control.

Consuming Vapors

Target player sacrifices a creature of their choice. You gain life equal to that creature's toughness.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Ageless Entity

Whenever you gain life, put that many +1/+1 counters on this creature.

Hatchery Spider

Reach
Undergrowth — When you cast this spell, reveal the top X cards of your library, where X is the number of creature cards in your graveyard. You may put a green permanent card with mana value X or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.