I couldn't miss the chance to practice my drawing!
The Elemental Yellow is an enemy from Final Fantasy Crystal Chronicles: Echoes of Time. Like their brethren, they are elemental in nature, in particular Thunder-elemental. Their main offense is to cast the Thunder spell at players from afar or if they're standing on the enemy, or to attack with a physical attack that can inflict Paralysis when up close.
An easy way to deal with them is to counter their Thunder spells by casting a Raise spell on it to cast Bio on the enemy, which will do heavy damage and Poison. If the Elemental Yellow does not die outright, Poison will interrupt its spells, making it easier to finish them off.
It is not recommended to jump on top of this enemy, as it will inflict Paralysis on the player.