Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Lumra, Bellow of the Woods

Vigilance, reach
Lumra's power and toughness are each equal to the number of lands you control.
When Lumra enters, mill four cards. Then return all land cards from your graveyard to the battlefield tapped.

Forest

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Prismatic Omen

Lands you control are every basic land type in addition to their other types.

Gaea's Cradle

{T}: Add {G} for each creature you control.

Quicksilver Fountain

At the beginning of each player's upkeep, that player puts a flood counter on target non-Island land they control of their choice. That land is an Island for as long as it has a flood counter on it.
At the beginning of each end step, if all lands on the battlefield are Islands, remove all flood counters from them.