Hippowdon is the second fully evolved weather starter to be introduced and the second fully evolved pokemon to have the ability sandstream. Sand is in my humble opion the second most useful weather and second most popular. Sand increases the special defence of rock type pokemon and dose passive damage to anything not a steel, rock or ground type pokemon. Sand is useful on stall teams to build up greater additional damage on offensive teams it provides extra special defence to monsters such as tyranitar and terakion, residual damage to weaken opponents offensive pokemon and finnaly makes stoutland a real contender for a sweet revenge killer in ou. Hippowdon is similiar in ways to donphan and plays the bulky ground type rather well and unlike donphan has slack off but also lacks rapid spin so he has solid lasting power add on stealth rock and you have a nice little weather starter here. Hippowdon is strong ressiliant and has good move pool to fill it's role as a weather starter, sadly the good news ends here, hippowdon has poor special defence and is badly weak to may top special threats such as celebi which brush off his attacks and push back with stab grass moves and he is weak to water a very common type, add to this the competition from the monster such as tyranitar and well you can see why hippowdon fell out of the lime light for a while bu never the less the hungry hungry hippo is a solid choice for stall teams and bulky offensive teams in general.