Mosstodon

Creature - Plant Elephant 5/3, 4G (5)
{1}: Target creature with power 5 or greater gains trample until end of turn.
Whether gargantuans are the manifested will of Progenitus or simply the result of overabundant resources is moot when a herd of them is thundering at you.
Illus. Parente

Gatherer Card Rulings [Nov 2009]

• 10/1/2008: The ability checks the targeted creature's power twice: when the creature becomes the target, and when the ability resolves. Once the ability resolves, it will continue to apply to the affected creature no matter what its power may become later in the turn.

Format Legality	Legal in Vintage, Legacy, Extended, Standard
Printings (1/9)	Shards of Alara (Common)