Lotus Cobra turns land entries into mana of any color. Whenever a land enters under your control, its landfall ability adds one mana, giving ramp and landfall decks extra resources during the turns when they are already developing their mana base. The trigger does not require Cobra to tap, so it can contribute immediately after it resolves.
Fetch lands provide two useful events. Playing Misty Rainforest creates one trigger, and sacrificing it to put a searched-for land onto the battlefield creates another. Those triggers can produce different colors, helping a multicolor deck cast several spells during the same turn. A land that enters tapped still triggers Cobra, so the extra mana can partly offset an otherwise slower land drop.
Exploration and Azusa, Lost but Seeking supply additional land plays, while Life from the Loam helps keep lands available to use them. Scapeshift can create a larger burst by putting several lands onto the battlefield together. These cards provide the additional entries that turn Cobra from a small accelerator into a more substantial engine.
The mana still follows the normal rule of emptying as steps and phases end. You cannot save a main-phase trigger for combat or a later turn without another effect. Landfall also uses the stack, so opponents can respond to the triggers even though Cobra ultimately produces mana. Keep a plan for spending the burst and enough other sources to function if the creature is removed before the lands you intended to play arrive.
