It looks to me as if he lost a toe nail and then got an infection in the toe. In any event, it is swelling and most likely full of infection. The thing is, when a chicken gets an infection, it is NOT liquid pus and will not drain out nor can it be extracted with a needle. It will be hard and rubbery and looked like cooked rubbery egg yolk or thick cheese.
I would immediately follow the bumble foot thread steps. Meaning, soak it in warm Epsom salt water, then make a long, deep incision over the swollen area. Dig out any infection. Keep soaking. Once you get it cleaned out, pack with Neosporin and wrap. Leave the wrap on for few days then take it off and let the wound air dry/heal. If I had a dollar for every chicken I've had to cut open a wounded area and dig out the abcessed infection, I would be a weathier woman.
I did have a rooster that had something similar once but it was his small "back toe". I could not find any infection, just swollen. Eventually his whole foot swelled to the point that it cut off circulation and his toes began to dry up and die. Eventually his whole foot fell off and he was left with a stub leg and his spur. More than a year later, he is still alive and well and mates and runs around the farm with the best of them. So, as a final disclaimer, if there is no infection and he keeps getting worse and you want to try one final desperate act to save him, I would amputate the toe. I've amputated a hen's leg and she also did great and healed just fine. Her problem was at her hock and it was severly deformed and kept her from getting around.
Best of luck whatever you do but I would do something soon since it has been this way since the first of the month at least.
Edited to clarify: If you decide to lance it open, make a long deep incision LENGTHWISE down the BACK of the toe. That way you won't be cutting into bone or slicing across tendons, etc.