Grover Underwood
Grover has been missing for 2 months; Percy and Nico decide to look for him on their way to the Underworld. Percy locates Grover through his empathy link in Central Park and finds him under a giant elm tree. Percy wakes him up by yelling, (via empathy link) "FOOD, PANCAKES!". He tells them he just took a nap and they figure out that Morpheus, the god of dreams, put Grover to sleep. In that way, Grover gives Percy and Nico info that some minor gods are on Kronos' side. He helps Nico and Percy get into the Underworld by playing his reed pipes to open up an entrance in Central Park.