The batteries corroded in elmo’s foot can this be repaired?

Pamela Adams you could most likely solder new contacts/springs in its place. Post some images so we can see how bad the damage is and where to attach the new ones. Agregar imágenes a una pregunta existente

You could get some wire and solder it onto the spring part. You could even bring some wire from the out side through the case. Of course I would suggest that you replace the spring contacts with something like this

Instead of cleaning it with baking soda use a diluted lemon juice solution to resolve some of the rust and debris from the alkali of the batteries. Once cleaned use a lightly oily rag to wipe down the lemon juice and lubricate the contacts.

Not a real bad repair and not to expensive