How to extract strings from column into a new column?

Question

I am new to google sheets.

How do I loop over column C and extract every occurence of Dog and Mouse together with its "index" A, C, D into columns E and F?

The best thing I can do right now is extract the strings row by row with

=IFS($C:$C="Dog"; $B:$B;$C:$C="Mouse";$B:$B;1=1; "") and =IFS($C:$C="Dog"; $C:$C;$C:$C="Mouse";$C:$C;1=1; "")

but this leaves free spaces in the new columns:

Answer 1

See if this works

=filter(B3:C, regexmatch(C3:C, "Dog|Mouse"))

or, depending on your locale

=filter(B3:C; regexmatch(C3:C; "Dog|Mouse"))