Grasp of the Hieromancer

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature attacks, tap target creature defending player controls."

Heavy Infantry

When Heavy Infantry enters, tap target creature an opponent controls.

Meteorite

When Meteorite enters, it deals 2 damage to any target.
{T}: Add one mana of any color.

Plains

Sentinel of the Eternal Watch

Vigilance (Attacking doesn't cause this creature to tap.)
At the beginning of combat on each opponent's turn, tap target creature that player controls.

Divine Verdict

Destroy target attacking or blocking creature.

Eagle of the Watch

Yoked Ox

Aegis Angel

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Aegis Angel enters, another target permanent gains indestructible for as long as you control Aegis Angel. (Effects that say "destroy" don't destroy it. A creature with indestructible can't be destroyed by damage.)

Valor in Akros

Whenever a creature you control enters, creatures you control get +1/+1 until end of turn.

Akroan Jailer

Mighty Leap

Target creature gets +2/+2 and gains flying until end of turn.

Serra Angel

Flying
Vigilance (Attacking doesn't cause this creature to tap.)

Charging Griffin

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Charging Griffin attacks, it gets +1/+1 until end of turn.