X-Ray Creepers are sometimes seen at night and will not burn with direct contact of sunlight. At night, there is a 39% chance that one will spawn in a 10x10 block radius. At day, they are neutral despite their hostility at night. When giving chase, they cannot explode. However, they can jump up four blocks, which can be a great source of amusement because they can appear to be "bouncing". They will simply ram into their target to deal damage.
X-Ray Creepers are found in swamp, ocean, and volcano biomes. It is suggested that the player search for them in swamp biomes rather than risking their lives in volcano biomes, even though they are most common there and have a 50% chance of spawning in a 4x4 radius.