Task: Text to Code
Input (English): Step 1: For each row in Ref_Characteristic_Types table, find the corresponding rows in Characteristics table.
Step 2: find characteristic_type_description of the results of step 1 whose characteristic_name equals catnip
Output (English): SELECT T1.characteristic_type_description FROM Ref_Characteristic_Types AS T1 JOIN Characteristics AS T2 ON T1.characteristic_type_code = T2.characteristic_type_code WHERE T2.characteristic_name = "catnip"