Ichor Stickers are Hardmode enemies that spawn in the Underground Crimson. They float around in the air. When tracking a player, they spit Ichor at them, which shoots several blocks and is affected by gravity. Their spit can inflict the Ichor Debuff, lowering your defense by 20. Upon death they will also drop Ichor. They are immune to the Poisoned and Venom debuffs.
Notes
Despite using Ichor as their main weapon, they are not immune to the Ichor debuff.
When killed by Ichor spit it will say the player was killed by Golden Shower, which is also a magic weapon the player can craft out of Ichor.
When they shoot Ichor, they shoot it in an arc.
Tips
To easily farm Ichor it is recommended for the player to create horizontal shafts in the Underground Crimson for the Ichor Sticker to spawn. A three block tall shaft will cause the Ichor Sticker to become stuck and barely able to shoot the player (as they shoot in an arc), with a four block tall shaft they become mobile but still have problems shooting the player. You will also have more room to deal with the irritating Floaty Gross, which can fly through blocks.
They appear to sink in any liquids they enter and can be effectively immobilized by water that is at least 4 blocks deep. While this will not prevent them from shooting if you are in sight, they can be easily dealt with using nearly any weapon available at start of hardmode.