Let me start by pointing out that, based on your description, your colleague is not incompetent and your colleague technically did not do anything wrong.
Is it wrong to say "we did" for tasks given to your team as whole? No, because after all everything is team's effort. At the same time, it is also not wrong to say "I did" when it is indeed only your effort alone. It's just playing with words for one's own gains.
What is very apparent, however, is your lack of confidence and interpersonal skills. You should talk to your manager (or skip to the next level) to assert the relative contribution between you and your colleague, based on hard evidence (git commit, wiki edit history, interviews with other teammates). Also you should do it as soon as possible after your colleague plays the word game while the manager for both of you still have fresh memory.
But now it might be too late for any of these. Move on to another team or another company.
Is it wrong to say "we did" for tasks given to your team as whole? No, because after all everything is team's effort. At the same time, it is also not wrong to say "I did" when it is indeed only your effort alone. It's just playing with words for one's own gains.
What is very apparent, however, is your lack of confidence and interpersonal skills. You should talk to your manager (or skip to the next level) to assert the relative contribution between you and your colleague, based on hard evidence (git commit, wiki edit history, interviews with other teammates). Also you should do it as soon as possible after your colleague plays the word game while the manager for both of you still have fresh memory.
But now it might be too late for any of these. Move on to another team or another company.