Gaba Ghoul

Gaba Ghoul is a Forest in addition to its other types.

Landfall — Whenever another land you control enters the battlefield, you gain an experience counter.

{3}{g}{w}{r}: Every land you control becomes a 0/1 Land Creature Elemental Spirit and gets +X/+X for half of every experience counter rounded up, you have until end of turn. You may activate this ability only once per turn.

https://en.wikipedia.org/wiki/Sicily