#032 Unova / #526 National
Species classification: Compressed Pokemon
Abilities: Sturdy – Leaves 1 HP when Pokemon would otherwise be one-hit KOed
Dream World abilities: Sand Power – Rock, Ground and Steel-type attacks get 30% power boost during sandstorms and gives user immunity to sandstorm damage
Location found (Black/White): Evolve Boldore
Egg groups: Mineral
Gender ratio: 50/50
Experience at lvl 100: 1,059,860
Base stats: 85 HP / 135 Atk / 130 Def / 60 SAtk / 70 SDef / 25 Spd / 505 Total
Effort values: 3 Attack
Evolution family: Roggenrola > Boldore at level 25 > Gigalith via trade
Unlike Golem, who gains a secondary Ground type, Gigalith maintains its pure Rock type, making it the only pure Rock third evolution to date. Whether that makes Gigalith more interesting or less interesting is debatable. Its STAB move options are limited because of its Rock type and completely dismal special attack stat, and your best bet is Stone Edge, TM71 (Gigalith also learns it at level 48). Sandstorm (TM37) is also a must, especially if you have a Gigalith with the Dream World ability Sand Power. The combination of its dismally low speed and low special defense are going to make it difficult to use in battle though.
Note: Wild Roggenrola and Boldore both have a 50% chance of holding an Everstone, so when you're ready to evolve Boldore into Gigalith, make sure you check for and remove the Everstone before trading, otherwise it won't evolve.