Jungle

The Jungle biome is a rare lush biome. Jungles typically generate near warm biomes, such as deserts and savannas. It has a total of five variations.

Description
The jungle is a heavily forested biome, rivaling the Dark Forest biome in tree density. Unlike the short and thick trees of the dark forest, however, jungle trees grow very high, and are the tallest trees in the game, with the tallest of them being well over 30 blocks in height. Oak trees may also grow within the tall jungle trees, and "bushes" made of oak/jungle leaves and a single log grow on the floor of the jungle, which frequently obstruct view of the bright green grass below. Many of the leaves and logs of both types are covered in vines.

Cocoa pods and melons generate on jungle logs and in patches on the ground, respectively. Melon patches generate somewhat more often than pumpkin patches do in other biomes. Additionally, the rare parrot and ocelot mobs exclusively spawn in jungle biomes, and chickens spawn at higher rates compared to other biomes. Occasionally, a jungle temple may generate within the foilage; as they are partially made of mossy cobblestone and also covered in vines, they can prove hard to spot from a distance due to the density of the trees. Jungle terrain is mildly hilly, not unlike the Forest biomes, but is exacerbated by the bushes that generate on the floor.

Survival in jungles can prove to be very difficult. While running out of wood likely won't ever be a problem, obtaining said wood can, due to the heights that jungle trees can grow to. Additionally, jungle trees are significantly less sustainable compared to other trees, as their leaves only drop saplings 2.5% of the time, compared to 5% for all other trees; this means large jungle trees often only drop enough saplings to regrow them and not plant any new trees, while small jungle trees may not even drop a single sapling. The dense foliage can easily get a player lost without some sort of trail marker, such as torches, and clearing the foliage for shelter is no easy task, due to both the heights it can reach and the sheer amount of it. However, ocelots and parrots can make for useful pets when tamed; ocelots can repel creepers, while parrots can alert players of nearby hostile mobs. Cocoa beans and melons can also be farmed for dye, food, trading, and other such purposes.

Variants
Other than the normal Jungle biome, there are four other jungle variants, for a total of five different jungle biomes.

Jungle Hills
Similar to the Wooded Hills biome, the Jungle Hills biome features steeper terrain, making it a more difficult variant of the already difficult jungle for survival purposes. Ocelots, parrots, and jungle temples may all still generate here, as they can in all jungle variants.

Modified Jungle
The rare Modified Jungle (known as Jungle M before 1.13) variant features much more mountainous terrain, being taller and steeper than jungle hills. The heights, combined with the thick foliage, renders the ground below almost entirely out of sight. This is among one of the most difficult biomes for survival, as the tall mountains being combined with very high tree density renders the landscape almost entirely unsuitable for shelter.

Jungle Edge
The Jungle Edge biome is a technical biome, intended to be a smooth transition from other biomes to the main jungle. Trees still generate here, though at significantly lower rates than the main jungle, roughly comparable to the rate of trees in the Savanna biome. The grass still takes on a very bright green color, the same as the main jungle. Jungle edges do not entirely border a jungle, however; they may be replaced by rivers, omitted entirely when jungles border already foliage-heavy biomes, such as forests and taigas (but not its variants), or widened when jungles border swamps.

Modified Jungle Edge
The extremely rare Modified Jungle Edge variant (known as JungleEdge M before 1.13) only generates in strict conditions, and is the rarest biome in the game, surpassing even the Mushroom Fields in rarity. In order for modified jungle edges to generate, a mutated biome (typically Swamp Hills) must generate right outside the edge of the jungle. This results in a double-layered transition, with a thin normal Jungle Edge bordering the mutated biome, and the modified jungle edge bordering the normal (or modified) jungle. As mutated biomes are already rare, and even more rarely generate on the edge of a jungle, and even more rarely generate in the exact required layout, the conditions for a modified jungle edge to generate are extremely rarely met, and when they actually do manage to generate, they are often only a few hundred blocks in length, making them one of the smallest biomes as well. Modified jungle edges feature the same smooth transition and lowered tree density that regular jungle edges have, though with more mountainous terrain and occasional overhangs.