Who is this Simhika?
Simhika appears in the malayalam text (attakatha) for the Kathakali play "Kirmiravadham" by Kottayam Tampuran (17th century). This text is among the four attakathas written by Tampuran based on Mahabharata (Bakavadham, Kalyanasaugandhikam , Nivatakavacakalakeyavadham are the other three). In this work, the author introduces two new characters outside of Vyasa's text: A rakshasa named Saardduula and his wife Simhika. Simhika also happens to be the sister of Kirmira. Saardduula is killed by Arjuna. To take revenge, Simhika decides to abduct Draupadi and present her to brother Kirmira. To achieve this goal, Simhika takes the form of Lalita (a beautiful woman) and approaches Draupadi. She wants to show Draupadi, a Durga temple in the forest. This is the context of the Ravivarma picture.
Later on in the kathakali play, Draupadi suspects foul play and refuses to go. Simhika resumes her original form and forcefully takes away Draupadi. Hearing Draupadi's cries, Sahadeva comes and cuts off the nose and breasts of Simhika. In the Kathakli play, while Kirmira stands on the stage, Simhika in a special kathakali "vesham" called niNam (blood) makes her appearance at the back of the audience, followed by lighted torch bearers, completly dripped in blood, accompanied by the beats of many chendas (drums).
This is followed by the encounter between Kirmira and Bhima and the killing of Kirmira.
Selections and commentary on Kirmiravadham are available in English in the book Kathakali Dance-Drama Where Gods and Demons Come to Play by Phillip B. Zarrilli.
The English translation of the episode, The Killing of Kirmira, in the Vana Parva of Mahabharata of Vyasa is available in the English translation by Kisari Mohan Ganguli here