Powershell (5.1), 2020 48* Bytes:
I setup my variables like this (which may not be correct):
|% $a = (7,13,9,2,10,2,4,10,7,13,4,9)
I then add that variable to:
$a |group|%{$m=@{}}{$m[$_.Name]=($_.CntCount)-eq2)}{$y$m}
OutputsThis outputs the "Name" and "True" or "False" (could also use the animals names & it would work)
To only list "True" or "False" it is 16 bytes:
|%{($_.Cnt-eq2)}
- group - Groups the items
- % - Abbreviation for For-Each
- $m=@{} - Assigns the new variable
- $_.Count-eq2 - Item count that equals 2
- $y - List each item with True or False (if it equals 2)
Results are similar to this:
*Note: This answer has been edited as I bungled things the first multiple times...