Here is the quote from someone that owns one. Now I don't know what to believe
"I have had a pair of Molly Miller blennies in a 120 gallon mixed reef tank for several years now. Haven’t seen them eat aiptasia anemones but have seen the female violently knock medium size (less than 1 inch) turbo snails from whatever substrate they were on. Then she waited for the overturned snail to come out of its shell to right itself, grabbed it by its foot, extracted it from the shell and ate it.
They produce babies frequently. Seems like almost constantly sometimes. They eat small to moderate quantities of nuisance algae in my tank, haven’t bothered any other fish, and are generally good community tank inhabitants. They feed aggressively on algae sheets and the usual meaty foods. Actually, they eat quite a lot for their size and you can forget about target feeding something like Elegance Coral a small piece of table shrimp. The female always takes it away. The male is charcoal black with many sky blue spots but he seems to always be incubating eggs and I rarely see him."