White mold on driftwood is it dangerous?

Not sure what it's called but it's very common when it comes to driftwood. it is a type of fungus yet it is harmless to the fish.

It will subside eventually, though it may get worse before it gets better. If it was me I'd remove it, but it can come back. There are different methods to clear it off, the most common is using boiling water (obviously not whilst it's in the tank).

While it looks pretty scary, it's actually on biofilm. Biofilm is basically the by-product of bacteria trying to digest organic waste. In this case, it's likely saps from the wood. No big deal, just unsightly. It should clear itself up within a few days. Shrimps, snails and some algae eating fish would be more than happy to much on it if you have them !

Perfect, it is a bit ugly but as long as it’s not toxic to my fish I will leave it alone. I am picking up a BN Pleco hopefully this weekend so he can munch on it if it’s still there.

This may or may not be toxic, so monitor the fish behaviour for several days.

There are many species of this sort of fungus, and while many are harmless, some are deadly toxic. I had the latter, and I know of others the same. Only a microbiologist examining the fungus can ascertain the species, and then know if it is toxic or not.

Most of this appears to be safe, and some fish, and shrimp and snails, will eat it. The toxic species will kill fish in time. When I had the latter, it first showed up as a slight cloudiness or haze in the water, something like a bacterial bloom but fairly light; I noticed this slimy fungus/mold-like whitish substance on large stretches of the wood. At the same time I noticed the fish respirating much faster, and they became lethargic, especially the cories. Cories seem especially sensitive to this, and they can die within a few days depending upon the circumstances.

The toxic fungus seems especially common with certain types of branch wood, like spiderwood, grapewood, and azalea. I have never seen it or heard of it on Malaysian Driftwood.

For me that resembles a bacterial bloom. It doesn't look like a particularly large one either. I am agreeing with what ShaenaB123 commented.