Luckily your cousin has you by his side, many scammers out there target people who don't understand crypto in depth and the DOGS page in CMC is the perfect place for them to get their victim.
This is nothing but scams, I headed to coinmarkcap myself and I saw many like it below many altcoins projects, he was lucky to have shared this with me, and he claimed that he already connected his special airdrop wallet, I just told him to abandon that wallet and create another, because I am sure it's likely compromised already.
Changing the address is important, but it's not a good move because your cousin could fall into the same trap without you know it. The best way is to educate him technically, you can teach him how to check the DApp connected to his address via
Revoke.cash & do revoke. They also support lots of networks which you can check one by one on
this page.
Z.H.I.E.N.D