A Jyk (ジャキール, Jakīru) is an enemy/trap in Super Smash Bros. Brawl's The Subspace Emissary mode. It is a non-sentient spike ball that either stays in one place or moves in a predetermined path. There are three varieties of Jyk, depending on the environment: Flame Jyks appear in caverns and ruins, Zap Jyks appear in the sky and in mechanized areas, and Hydro Jyks appear near lakes, rivers, and frozen tundra. Besides the effect of the damage they deal, there is no difference between the types.
Jyks are immune to all attacks and therefore cannot be destroyed, making them more like an obstacle than an enemy. It also cannot be captured by a trophy stand; one must clear Boss Battles with 20 characters to get the Jyk trophy.
 Damage taken
 Trophy description
A six-spiked enemy. Attacking a Jyk will do no damage, as they can't be defeated. But you'd better believe that a Jyk will deal out damage to you if you get too close. This foe epitomizes player-hindering obstacles--it gets in your way... and it hurts. It definitely isn't thought fondly of by the characters in the game. It may have something to do with its SHARP SPIKES! Ouch.
- Despite Jyks being called out for their spikes in the trophy description, the Jyk's hitbox is within its core, not on its spikes.
- Although they cannot be defeated, Jyks will display a health bar when attacked. The bar appears completely empty, as the game considers them to have a health of -1.
- Hydro Jyks are the only enemy that use water to attack. It is theorized that as a result, the damage they deal cannot be reduced by any stickers.
- Zap Jyks and Hydro Jyks have swapped sound effects; Zap Jyks create water sound effects, while Hydro Jyks create electric sound effects.