Ronda Rousey just put Amanda Nunes on notice with these intense Instagram pics

This will mark her first return to the ring since getting knocked out by Holly Holm in 2015.

For the first time since getting knocked out by Holly Holm back in November 2015, Ronda Rousey will step inside the Octagon on December 30 for UFC 207 where she will take on current bantamweight champion Amanda Nunes for the Women's Bantamweight Title.

Shortly following getting upset by Holm, Rousey spent some time hitting the entertainment circuit, hosting "Saturday Night Live" and gearing up for several movie appearances, but recently she's been all business, as she showed with several intense training photos that she recently posted on Instagram.

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It sounds like Nunes may have gotten word of the new-and-improved Ronda considering just last night, it was reported that Nunes had to miss a UFC 207 event on account of her feeling sick.

Could Rousey have Nunes feeling shook?