Realistic advice is good advice. Most non Cory catfish are still wild caught, and most free swimming catfish have big mouths and get pretty big pretty quickly. It is stupid to put a 2 inch catfish in a tank and not expect it to eat everything pretty quickly. That's what they do. Seen it happen plenty of times. 'My pretty little fish is now 10 inches long and has eaten everything.....'
The above might sound harsh, but it is realistic and accurate. Dodging the issue in the name of 'niceness' is not going to help.
Incidentally did you know these fish are venomous, so try to avoid touching it. It's not dangerous, it's pretty similar to a wasp sting