Beaker

I blame myself for allowing Mrs Gruff to visit the library unaccompanied. She hadn't been gone for very long (the library is about a hundred yards away) when she called to ask me if I wanted a goldfish. Apparently the librarian's staff had found it dumped, in its tank, on the litter bin outside. They were so delighted that we'd taken it that they let Mrs Gruff have the two withdrawn books she was going to buy gratis. It has a mouth like Beaker, from 'The Muppet Show', and is almost the same colour, so we had no difficulty deciding what to call it.