I couldn't miss the chance to practice my drawing!
Weight (ヘヴィ, hevi?, lit. Heavy) is a common status ailment in Final Fantasy XI. There are a number of enemy abilities that can impose this ailment. Players can also impose this on their enemies by casting the Red Mage spells Gravity or Gravity II.
Weight will reduce the land speed of a character and also lower his evasion characteristic. This will make it harder for the effected target to avoid attacks and also almost impossible for it to run away or catch up to a target. For this reason, it is very useful in the strategy known as kiting. Due to some players soloing Notorious Monsters far above their level while taking very long times to do so, the development team has made every NM created in the past few years completely immune to the status.
A similar status, Heavy, appears in Final Fantasy XIV. It's afflicted by various enemy abilities. The Conjurer ability Stone inflicts it on enemies. Many bosses are not affected by it at all.