Jasper Sitwell

Jasper Sitwell was a S.H.I.E.L.D. agent and Phil Coulson's partner in bureaucracy: in The Consultant the two of them rig a meeting so General Ross will refuse to hand over the Abomination, and in Item 47 he tracks down two bank robbers with a Chitauri gun and recruits them instead of killing them. He was also Hydra the whole time. The Winter Soldier exposes him, Steve Rogers, Natasha Romanoff and Sam Wilson force him to give up Zola's algorithm, and the Winter Soldier kills him for it.

First turns up in Thor.