Moving very slowly I managed to lay on the ground and get close enough (didnt have more than 50mm in my lens) to this lovely "toad". Once I was done, he/she decided it was enough and went away.
An anecdote on this photo: It was the second time I was meeting my fiance's family, we had just finished having dinner when I saw this toad near the table and I didnt have better idea than go and lay on the ground with the camera and external flash... When I looked back everyone was watching me :P
BTW about the classification of the specie, looks like "Rhinella" species were once included in the "Bufo"s but now they are considered a subgenus by many herpetologists.
''Rhinella arenarum'' is a species of toad in the Bufonidae family that is found in Argentina, Bolivia, Brazil, Uruguay, and possibly Paraguay.
Its natural habitats are subtropical or tropical dry forests, subtropical or tropical dry lowland grassland, rivers, intermittent freshwater marshes, sandy shores, coastal freshwater lagoons, rural gardens, urban areas, ponds, seasonally flooded agricultural land, and canals and ditches.