Hero on the Halfshell
“Wealthy noble Teledji Adeledji has had his prized pet, a rare gil turtle, kidnapped by ruthless bandits who seek a sizable ransom for the gentle wavekin's return. Always a man of principle, Teledji Adeledji has decided that instead of caving to the bandit's demands, he will offer the ransom to anyone who can safely retrieve his pet from the clutches of evil.
After weakening the gil turtle, slay fire sprites and use their cores to light a special herb on fire. The smoke released should be powerful enough to put the creature to sleep, but only if the turtle is close enough to the flames.— In-game description
Hero on the Halfshell is a level 15 guildhest introduced in patch 2.0. It intends to teach basic boss mechanics.
Guide
Gil Turtle
In Hero on the Halfshell, you are required to capture a giant turtle mini-boss named Gil Turtle.
Before you start the fight, locate the environmental object Herb Patch in the boss room. You will need to interact with it to capture the boss. When you start the fight, defeat the Amateur Raider and Eft adds and have your tank take Gil Turtle's aggro.
After the turtle has taken some damage, a Fire Sprite spawns. Your party needs to kill the Fire Sprite as soon as possible. The Sprite drops an item that allows your party to use the Herb Patch. Pull the Gil Turtle to the Herb Patch then interact with the Herb Patch. The patch emits a column of smoke that put the turtle to sleep, allowing you to capture it.
If the Gil Turtle is accidentally killed, it will respawn after a few seconds.
- Be sure to lure the Gil Turtle to the herb patch before lighting it.
Loot
Reward: 
1,510 experience, 
80 gil