Ghost disciples are followers of Necrovarus. They worship the Ectofuntus in Port Phasmatys. After worshiping the Ectofuntus you can talk to the disciples to receive Ectotokens. You may need a Ghostspeak amulet while talking to Ghost disciples; if you don't, they say "wooo woooo wooooo woo". Note that a Ghostspeak amulet is not required when collecting Ectotokens by right-clicking them and selecting Collect. The ghost disciples, like most ghosts living in Port Phasmatys, have a green glow to them. The maximum tokens they can hold before forcing you to collect them is 2555.