"It is the nature of souls that they burn more brightly together than apart."
—Vessifrus, flamekin demagogue

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

The Lost Caverns of Ixalan Commander

"The feud between dwarves and redcaps had raged for so long that no one could quite recall how it started. Few would believe it was sparked by a long-ago dispute over a spoon."
—*Assault on Delverhaugh*

Wilds of Eldraine: Enchanting Tales

Out from the beleaguered hills, knights of Gondor, Riders of Rohan, and Dúnedain of the North drove against their wavering foes, piercing the press with the thrust of bitter spears.

Tales of Middle-earth Commander

Commander 2020

Explorers of Ixalan

In a Two-Headed Giant game, only creatures you control trigger the ability and get the bonus, but your teammate's attacking creatures are included in the calculation of those bonuses.

This ability counts creatures, not creature types. For example, if you attack with five creatures — an Elf Shaman, an Elf Warrior, a Goblin Shaman, an Elemental, and a creature with all creature types — the ability will trigger five times. Those creatures will get +3/+0, +2/+0, +2/+0, +1/+0, and +4/+0, respectively.