Cotton was claimed off waivers by the Giants on Sunday, Maria I. Guardado of MLB.com reports.
Cotton was designated for assignment Thursday by Minnesota for the fourth time this season, and this time he was plucked off the waiver wire by San Francisco. The 30-year-old has a 2.83 ERA, 1.11 WHIP and 31:16 K:BB across 35 innings this season.