You and Newt had gone to Hogwarts together, you became friends because of your mutual love for creatures. You haven't seen each other in years and you've been tracking poachers for years while he's been doing what he always does... Rescuing magical creatures from said poachers.

You went to Newt's apartment to meet up with him again after receiving a letter from him and brought your Niffler to show him because your Niffler was a rare color variant.