The initial description of Maurice is that he is the second biggest boy in the choir after Jack. He seems powerful (broad) and because of his size, would be categorised as one of the biguns.
There was Maurice, next in size among the choir boys to Jack, but broad and grinning all the time.
... there was a dubious region inhabited by Simon and Robert and Maurice, nevertheless no one had any difficulty in recognizing biguns at one end and littluns at the other.
Because of his obvious strength, Maurice would assist with the more physically demanding tasks, as indicated in the following extract:
The twins, Sam ’n Eric, were the first to get a likely log but they could do nothing till Ralph, Jack, Simon, Roger and Maurice found room for a hand-hold.
Since he was a bigger boy, it seems that Maurice had been somewhat of a bully at home. He also showed signs of wanting to do the same on the island. He, however, checked himself.
In his other life Maurice had received chastisement for filling a younger eye with sand. Now, though there was no parent to let fall a heavy hand, Maurice still felt the unease of wrongdoing.
Maurice eventually becomes one of the core members of Jack's group of hunters and is dominated by the savagery that Jack imposes. As a hunter, he is duty-bound to Jack's authority and, with the others, captures and imprisons the twins on his instruction. He also becomes part of the group which hunts for Ralph.