At present there's at least a species of ladybug that often has an odd number of chromosomes - some members of that species has a couple of chromosomes fused. This doesn't significantly impact fertility: if a ladybug only has one fused chromosome then during meiosis the unfused counterparts just line up end to end next to it.

The ancestors of humans also had a similar deal but afaik there are no modern humans with unfused chromosome 2.