Akoum Hellhound

Landfall — Whenever a land you control enters, this creature gets +2/+2 until end of turn.

Magic Online Promos

Hellhound packs roam the Spikefields, basking in the harsh sunlight and lighting the night with their flames.

Zendikar Rising

A landfall ability doesn't trigger if a permanent already on the battlefield becomes a land.

A landfall ability triggers whenever a land you control enters for any reason. It triggers whenever you play a land, as well as whenever a spell or ability puts a land onto the battlefield under your control.

Whenever a land you control enters, each landfall ability of the permanents you control will trigger. You can put them   on the stack in any order. The last ability you put on the stack will be the first one to resolve (As a result, you can have those abilities resolve in the order of your choosing.).