The Dog House Multihold's free spins bonus stands out with its innovative "Multihold" feature. Instead of a traditional free spins round, players start with a single 5x3 grid and can unlock up to three additional grids by landing Scatter symbols. Each time a new grid is unlocked, the player receives additional free spins and any existing sticky Wilds are copied over to the new grid, increasing the potential for bigger wins. This progressive unlocking of grids adds an element of anticipation and excitement to the free spins round.