Sticky Bomb

Sticky Bombs are a Type of Explosive Consumable added in the 1.0.2 patch, crafted from one bomb and 5 gels.

They will stick to the first solid block they land on and do not roll, which allows them to be more easily controlled at the cost of shorter overall reach.

See http://www.terrariaonline.com/threads/patch-notes-1-0-2.10181/