Physically, the Blob's body shows signs of decay, not unlike that of zombies. Furthermore, its face appears to have dissolved into boils, and its back has increased size from muscle growth to the extent of needing a harness. This growth also has a yellow eye as seen from behind, similar to G-viruscreatures , which serves as a weak point.
It appears to possess superior strength, based on the fact that its anchor is far larger than itself, and its ability to lift its enemies off the ground single handed. It also seems to have heightened senses, as one of the Blobs encountered by Chris Redfield and Jill Valentine was able to deduce that they were directly behind a breakable wall.