The Ninja Armor is crafted using Orange Leather (recipe is leather and orange dye). The helmet requires a headband (fill the middle row with black wool) as well. It is as protective as leather armor. Once you have the full set, you can begin upgrading. A Ninja Helmet will allow you to see invisible things as well.

Path 1

Shadow Dash ($300: Special Ability: Use Space once every 30 seconds to teleport you 10 blocks directly forward. You might teleport inside a block: beware!)

Sharp Shurikens ($350, When using a Shuriken, it does +2 damage.)

Double Shurikens ($850, you can set in the upgrade menu to fire 1 or 2 shurikens at once.)

Bloonjitsu ($2750, you can now fire up to 5 shurikens at once, your Shadow Dash can go up to 20 blocks and will never teleport you into a block, and you have a 25% chance of evading any attack.)

Path 2

Homing Shurikens ($250, any shuriken you use will home in on the closest or strongest target.)

Distraction ($350, when you attack, the target will move away and not attack you for 3 seconds. This doesn't affect blimps or bosses.)

Flash bomb ($1800, your shurikens have a 10% chance to paralyse anyone within 3 blocks for 5 seconds.)

Ninja State ($3000, you can use a special ability, Ninja State. With it, for 1 minute you gain Speed 4, and shurikens deal +1 damage per upgrade, with an extra +1 for being a ninja, so you may get up to +9! You are invisible while standing still, and Shadow Dash has no recharge period and will never teleport you into a block.)