Fadoodlebop
A fadoodlebop is when you can't think of the name of the thing you're talking about. It's also what you call a nameless thing or a dumb island in Animal Crossing.
'That thing is a fadoodlebop. I can't think of a name for it.'
'That island is a fadoodlebop. It's just a dumb island.'
'He called my pet a fadoodlebop. That's the worst insult ever.'