Speaking through an interpreter at Celtic Park, he said: "It is my biggest achievement so far and I am delighted to finally sign a contract with such a big team.

"Celtic fans are going to see a player who has come here to score a lot of goals.

"That is what I am planning to do and I want to bring a lot of happiness to them.

"Scottish football is slightly different to what I experienced in Poland.

"It is more aggressive but I am up for it and will do my best.

"I have come here to win a lot of trophies with the team and do my best, as I said before, to bring a lot of happiness.

"That is my main goal."

Celtic's first signing of the January window has arrived ostensibly as back-up to main striker Odsonne Edouard.

However, with the William Hill Scottish Cup tie away to Partick Thistle on Saturday on the horizon, the 21-year-old said: "I don't expect to be in the first team after three days.

"I would love to be in the first team, however, I will do my best to fight for my place.

"At the end of the day it is the coach's decision."