Yes, you're right. I used Array#shift with the input array, that's a bad thing.

Copying solved the issue. Thanks!

Testig for Leon McNichol, Galatea, Sylia Stingray, Anri
It should work for random inputs too -  Expected: "Sylia Stingray and Anri like this", instead got: "Leon McNichol, Galatea and 2 others like this"

Looks like random test examples shift two first elements from the array. It's currently impossible to complete this kata, you either have basic test passing and random failed or none at all after hacking.
Also 'Testig' is misspelled.

Please, fix the tests!