[3][8] Croker began working with Nat Buchanan in 1877, and became considered his 'right-hand man', and in the same year they became the first Europeans to cross the Barkly Tableland.
Croker was then employed on a number of Buchanan's properties, including Wave Hill Station (which was established in 1882), where it is recorded that he was involved in reprisals and massacres of the Gurindji people living there.
[9] In 1882 he was also involved in the Red Lilly Lagoon Massacre on Elsey Station in which, in reprisal for the 15 July death of Duncan Campbell in which 20 Mangarayi people were killed.
He had brought with him Flannigan, who he had known for some time and had recruited from Wave Hill Station, to construct cattle yards; it was offered as a week of work.
Though not a good tracker, he had all the other bush craft of [an Aboriginal person] ... Not a great stockman and horseman ... yet he was equal to any bush emergency ... never enthusiastic, yet never downhearted, he was generally cheerful, imperturbable, with a tendency to romance, and to chaff and banter.Croker's grave is located at Auvergne Station, 59 kilometres (37 mi) from Timber Creek.