The 25-year-old has signed a permanent deal with the Reds after Barnsley and Telford agreed an undisclosed fee.
Speaking to Barnsley Player, Phenix said. "I'm chuffed to be bits. It's a bit overwhelming to be honest.
"It came about last night. My Manager told me about the interest and it was a no-brainer.
"It all happened overnight and was a bit mad! I just thought I'd go for it and hopefully I can bring some success.
"I was used to training on Tuesday and Thursday nights. I'm looking forward to training every day and getting as fit as I can."
The 6ft 1in striker has netted six times so far this season whilst operating both up front and from out wide.
Phenix has penned a contract at Oakwell that will run until 30th June, 2016.
