Corrosive; highly exothermic reaction with water. Burns from sulfuric acid are potentially more serious than those of comparable strong acids (e.g. hydrochloric acid), as there is additional tissue damage due to dehydration and particularly due to the heat liberated by the reaction with water; i.e. secondary thermal damage.
The danger is greater with more concentrated preparations of sulfuric acid; however, even the "dilute" ~ 0.1 M H2SO4 will char paper by dehydration if left in contact for a sufficient while.
MSDS for H2SO4