Have

Moment of Heroism

Target creature gets +2/+2 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Angel of Vitality

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

Dawning Angel

Flying
When Dawning Angel enters, you gain 4 life.

Goldmane Griffin

Flying, vigilance
When Goldmane Griffin enters, you may search your library and/or graveyard for a card named Ajani, Inspiring Leader, reveal it, and put it into your hand. If you search your library this way, shuffle.

Daybreak Chaplain

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Impassioned Orator

Whenever another creature you control enters, you gain 1 life.

Twinblade Paladin

Whenever you gain life, put a +1/+1 counter on this creature.
As long as you have 25 or more life, this creature has double strike. (It deals both first-strike and regular combat damage.)

Plains

Fencing Ace

Double strike (This creature deals both first-strike and regular combat damage.)

Serra's Guardian

Flying (This creature can't be blocked except by creatures with flying or reach.)
Vigilance (Attacking doesn't cause this creature to tap.)
Other creatures you control have vigilance.

Loxodon Lifechanter

When Loxodon Lifechanter enters, you may have your life total become the total toughness of creatures you control.
{5}{W}: Loxodon Lifechanter gets +X/+X until end of turn, where X is your life total.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Savannah Sage

When Savannah Sage enters, you gain 2 life.

Ajani, Inspiring Leader

+2: You gain 2 life. Put two +1/+1 counters on up to one target creature.
−3: Exile target creature. Its controller gains 2 life.
−10: Creatures you control gain flying and double strike until end of turn.