The three Pareroultja brothers – Edwin, Otto and Reuben – made a huge contribution to the quality and distinctiveness of the Hermannsburg School. The oldest of the Pareroultja brothers, Otto, started to paint in 1946 when aged 22 years, after Enos Namatjira and Walter Ebatarinja had started to paint seriously. Edwin had been painting for a couple of years, when Rex Battarbee spoke to Edwin and said that it was a pity that Otto and Reuben were not doing more work.
Rex stated “At this time [late 1945] they were not doing very much, (although they had started to experiment before Edwin started painting seriously), probably because of lack of encouragement and because they did not know if they were on the right lines in trying to do something according to their own outlook.” Otto had struggled with drawing from around 1940.
In 1946 Edwin Pareroultja seems to have actively guided both of his brothers: first Otto and then Reuben. Otto began to paint seriously in 1946, after starting 1945.
Otto Pareroultja portrayed country that was vibrant and rhythmic. Otto’s paintings exude a high sense otherness, the other world of his tribal relationship to his totemic countries. The sometimes animate looking trees were marked to suggest totems with totemic-like striped markings. Any urge to describe them as ‘anthropomorphic’ is resisted as they may not be meant to attribute human qualities to the trees, but possibly some non-human spirit or ancestor.
As observed by Ian Burn and Ann Stephen in Heritage of Namatjira : ‘In Aboriginal terms, the landscape is not mute, nor other; the history of the land embodies its cultural transformation, one through which Aborigines regard the landscape as an objectification of themselves’. Catherine H Berndt and Ronald M Berndt in Aboriginal Australians, refer to the spiritual essence of the country as the active ingredient of life, while the country is not usually referred to as taking the initiative, such as in starting bushfires. 
Sometimes attitudes emitted in his paintings ranged from tranquillity and delight to drama and anger. On at least one occasion he portrayed fierce conflict between elements of the totemic topography. He engaged pictorially with his audience by using expressive trees, hills and cliffs ‘to mime’ events theatrically. As he gained confidence, rhythm was employed with increasing dramatic effect.
Otto’s rhythmic approach was an action process no doubt borne from his experiences of song and dance. He was a baptised Christian, who also celebrated his traditional culture. Significantly, his family were known for their diffidence toward the Mission.  Consciously Aboriginal, he avoided using symbols unavailable to those ‘who were not in the know’. Otto was a founder and master painter of the Hermannsburg School.
Rhythm came first and intense colour came later. As he gained confidence, rhythm was employed with increasing dramatic affect to engage with his audience. First, he rounded geometric patterns to give vibrancy to rocks and hills. Second, he evolved a patterning style of rhythmic rounded marks with curved tails which enabled him to portray parts of totemic hill structures as pulsating (like a beating heart).
Otto seemed to invite his audience to consider whether the animated trees are participants or observers in the stories implied in the paintings. Likewise the viewer may consider elements of the topographic landscape as participants or observers or as features making up a scene. Otto was about engagement and thus embraced his audience.
Most of Otto’s paintings do not indicate the location in their titles, nor any helpful inscriptions about locations. The locations for his paintings included actual and archetypal scenes of the wide area of the Finke River Mission, including Haasts Bluff and Areyonga to the west of Hermannsburg, Palm Valley to the south, Glen Helen and Ormiston to the north and eastward including to Jay Creek and Heavitree Gap at Alice Springs. Many, being based on legends, would have been ‘memory’ paintings, a concept so important in Aboriginal tradition.
Otto married Laurel Kekainan, a Loritja woman, and as at 1957 they had three children, including future artist Trevor. Otto and Laurel were in Alice Springs when Trevor was born in 1941. Otto was Western Arrernte, Subsection (Skin) Kngwarreye.