Raging Heroes are no longer selling their Lamassu head after a complaint from Games Workshop.
From their announcement:
It is with our deepest regret that we have to announce that the Lamassu head is no more part of our Manticore kit We recently received an email from a Games Workshop attorney claiming that our Lamassu head was too similar to their Chaos Dwarves’ Lamasu and asking us to stop selling this head.
At this point in time we don’t have the time to further investigate this mater and so we’ve decided to currently withdraw the Lamassu head from sale, either online or in shop. We are sorry if you were planning to get one. So please note that at this point in time there is no more Lamassu head available with our Manticore kit.