Clown

The Clown is a rare Hardmode enemy that appears during Blood Moons. The clown's primary weapons are smiley bombs which will do standard bomb damage to a player or NPC when they detonate (up to 100 damage), but will not destroy player-placed tiles (as of v1.2). Its bombs can be shot out of the air with most weapons. Touching the clown itself inflicts melee damage and has a chance to inflict the Confused debuff.

On the console/mobile ports of Terraria, or any PC version previous to v1.2, the smiley bombs it throws are treated the same as player-thrown bombs and will destroy nearby blocks when they go off, like a normal Bomb; this makes Clowns a serious hazard to any structures on these versions of Terraria.

Once you have defeated at least one Clown the Clothier will start selling the clown costume.

Console/ Mobile Tips

 * Clowns are the only enemies that actually put structures in danger. Here are some tips to protect your work:
 * Replace your House's outer framework with Dungeon Bricks or raw Hardmode ores (Cobalt, Mythril, Adamantite), which are impervious to bombs.
 * Blocks that are impervious to explosions will not shield the blocks behind them though, so merely encasing your House with these will not provide much protection. A fair depth of a structure's outer framework will need to be replaced, or barricades made of impervious blocks can be constructed a fair distance away from vulnerable structures.
 * Build your house underground, or hide deep underground until the night is over, so that Clowns have no chance to spawn.
 * Travel several screens away from any structures you care to protect. Like all enemies, Clowns will only spawn near a character.
 * Build your house floating a fair distance above ground, or mine away enough blocks beneath and around your existing House (essentially making it floating), so that Clowns and their Bombs cannot reach it.
 * Put moats with Lava on either side of your base. Optionally you can install Active/Inactive stone drawbridges to make it easier for you to access your house. Note that Inactive Stone Blocks will still break from explosions.
 * With enough investment, a buffer of chests or storage items planted on tiles will offer complete protection against all explosives. See Storage Items.
 * The Clowns bomb have a 3x3 blast radius meaning a bomb proof wall must be 3 or more blocks thick.

Trivia
The color of the clowns outfit may be a reference to the batman villain The Joker.