Colonel Hargis was played by Jack Radis in The Blob.
Colonel Hargis is the military leader of the team lead by Dr. Meddows to find and recover the satellite with the bio-weapons experiment. He follows Dr. Meddow´s orders and even partially agrees with them until the Blob kills him making him realise in full how dangerous it is. Then he takes command and tries to kill the Blob with machine guns and explosives, but to no avail.
The Blob then appears out of the sewer and begina to kill people. Then it is about to devour the Colonel. In order to prevent that, he blows himself up with the help of two grenades he had in the hopes of harming the creature, too, but to no avail.