From American Spanish lobo (“wolf”) (/ˈloβo/), reinterpreted as or conflated with loper (“one who lopes”); compare the alternative forms which reflect other re-interpretations and conflations.
Meanings
(Southwestern, US, dialectal) A wolf, especially a grey or timber wolf.
When I was still some distance above the ford, about a dozen prairie wolves and one loper* wolf ran up from the water. They told me that there were no Indians near here or they would not be here; and they were not here long, either. [...] the big loper left on a slow gallop [...]
Loper, corruption of Sp. lobo, wolf. 1905 April 22, C. Blanco, “Flanking a Wolf”, in Forest and Stream, page 314:
Besides the cattle company paid a bounty for each coyote, loper wolf, panther, bobcat or bear. We had to buy our own six-shooter but the company furnished ammunition free. So it can be seen why most cowboys were pretty good shots. 1936, James Shannon Buchanan, Chronicles of Oklahoma: