"Every white tiger possesses the wisdom of its entire race. Even though they are fiercely independent creatures, the bond between them is unbreakable and they take great joy in spending time with the others of their kind."Summon White Tiger is a second-level Nature Magic spell in Heroes of Might and Magic IV that costs three spell points and summons a number of white tigers based on the level of the caster.
As with most level 2 and 3 summoning spells, the number of white tigers you can summon with this spell probably isn't enough to really affect the battle. Don't cast this unless you're fairly desperate for some melee support and you don't have any better summoning spells available.
Even a handful of White Tigers can actually be useful in the early game (i.e. grabbing resource structures away from wolves and faeries), and as a level 2 spell, it can actually be had that early.