Exhibit 3.21

CERTIFICATE OF FORMATION

OF

GCER ONSHORE, LLC

1. The name of the limited liability company is GCER Onshore, LLC (the “Company”).

2. The registered office of the Company in the State of Delaware is located at the Corporation Trust Center, 1209 Orange Street, Wilmington, New Castle County, Delaware 19801. The name of its registered agent at such address is The Corporation Trust Company.

IN WITNESS WHEREOF, the undersigned has executed this certificate this 19th day of November, 2010.

By: /s/ Sarah E. McLean                                    

Name: Sarah E. McLean

Title: Authorized Person

STATE OF DELAWARE

CERTIFICATE OF AMENDMENT

1.	Name of Limited Liability Company: CGER Onshore LLC
2.	The Certificate of Formation of the limited liability company is hereby amended as follows:
		1. The name of the limited liability company is       Talos Gulf Coast Onshore LLC
	IN WITNESS WHEREOF, the undersigned have executed this Certificate on the 6th day of July, A.D. 2015.

By:	William S. Moss III
Authorized Person(s)
Name:	William S. Moss III
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