It looks like a Heliofungi and if it is Heliofungi are harder corals to keep for anyone.
(taken from a website)
"Although the skeletons of corals in the genus Heliofungia are nearly identical to those of Fungia, there is no mistaking them for each other. Heliofungia have long tentacles, often resembling a sea anenome more than a stony coral. In fact, the 'Long Tentacle Plate Coral' (Heliofungia Actiniformis) has the longest polyps of all corals. Often the tips of these tentacles are brightly colored; seen in pink, purple and green. Reef aquarists should note, these corals are much more delicate than Fungia and require regular feeding."