Tyga Sued -- Video Vixen Claims Sexual Assault by a Yellow Rabbit

Tyga's "Make It Nasty" video is biting him in the ass again -- a fourth woman is now suing ... claiming she was lied to about nudity in the video, and sexually attacked by a rabbit ... and we don't mean the vibrator.

The woman, Allison Brown, is suing Tyga and his record label ... Young Money Entertainment -- claiming she was approached in November 2011 by a man who said he was tight with Tyga, and she had a "good look" for his music video.

In the suit, Brown claims she showed up for the shoot at a Hollywood Hills mansion where producers proceeded to ply her with booze -- even though she was only 20 years old at the time. She alleges no one ever asked for ID.

This is when things took a nasty turn, according to the suit. Brown claims someone in a yellow rabbit costume grabbed her from behind her hips and started dry humping her -- and when she pulled away from the rabbit ... another man on set grabbed her breast.

In addition, Brown alleges she had been coerced to remove her top ... and promised her nipples would not be exposed in the final edit of the video.

TMZ broke the story ... 3 other women have already filed a similar suit against Tyga ... claiming their boobs were exposed to the world when the video was released.

Brown is suing Tyga for sexual battery and a slew of other despicable acts ... including fraud, invasion of privacy, and infliction of emotional distress.