Raspberry peanut butter mead, this happened after racking into tertiary. Primary and secondary had raspberries freefloating in the container, so it miiiight just be floating bits of raspberry. When I shake it up, they briefly sink and float back up.
Looks like chunks of berries, not like mold. How did you rack exactly?
Sniffing it is your best analysis available. Just scoop some and sniff, if you don't like it, you won't like the rest!