C.Q. Cumber

"This is C.Q. Cumber, a humble sea cucumber who works as a subway conductor and guide to the underground test facility. Despite his mysterious looks, this diminutive dude is a total pro and takes his job quite seriously. Whenever you’re in trouble, try talking to him."

- Live from the Squid Research Lab

C.Q. Cumber is a character in the Octo Expansion for Splatoon 2. He is a translucent blue sea cucumber (likely a sea pig) wearing a train conductor's hat. He is an employee of Kamabo Corporation, serving as the conductor of the Deepsea Metro, and is shown interacting with Cap'n Cuttlefish.

He was first shown in the March 8, 2018 Nintendo Direct explaining the usage of the subway map to Agent 8.

Octo Expansion
Upon receiving a CQ-80 and a CQ Card from the Telephone, Cap'n Cuttlefish and the newly christened Agent 8 board the Deepsea Metro. Once aboard, C.Q. Cumber introduces himself to the Captain and the Agent and adds 1000 CQ Points to the CQ Card.

At each station, C.Q. Cumber instructs Agent 8–and, thus, the player–of the objective, the hazards, and requirements of the upcoming test. If Agent 8 does something that either fails the test's requirements or precludes the possibility of completing the objective (e.g. causing an 8-Ball to fall off of the stage), then C.Q. Cumber informs him or her of this before declaring the test failed.

Following the defeat of the final boss, C.Q. Cumber mentions that Kamabo Co. has ceased to exist. Despite this, he assures Agent 8 that the Deepsea Metro is still running, allowing Agent 8 to complete any tests that he or she missed.

Trivia

 * His name is a pun because it sounds exactly like his species name, "sea cucumber."