Lion Chariots

Not all white lions are killed out of hand. The High Elves take no joy in needless slaughter, and often stay their blades should cubs be discovered. These infants would doubtless become savage and deadly beasts if they were left in the wild, but with expert care, the young white lions are raised to become as loyal as Griffons. These 'tame' white lions swiftly form a bond with the Chracian hunters that foster them and later serve the armies of Ulthuan as War Lions.

So do many of the Phoenix King's bodyguard ride to battle in Lion Chariots. Each of these white-timbered constructions is drawn by a pair of snarling War Lions whose savage power is belied by their feline grace and elegantly plaited manes. Whilst a Tiranoc Chariot might sweep across the battlefield carefully picking at the foe, a Lion Chariot of Chrace charges headlong into the fray. As the War Lions tear into the foe with fang and claw, the crew fight from the chariot platform, cleaving heads from shoulders with every axe-blow. Such daring charges have become the hallmark of the Lion Chariots, earning them a well-deserved reputation as the bane of even the most determined shieldwall.

Source
Warhammer Armies: High Elves (8th Edition) -- pg. 46