Eva Allister is a villainess from the comic Batman '66 #69. She appears in the story Hunt The Croc Down.
Eva is the supposed ex-girlfriend of Waylon Jones (Killer Croc). When Batman and Robin come to her house to ask about Killer Croc she invites them in and offers them a drink.
However inside the house hiding is Killer Croc himself, who attacks as Batman suspects Eva may have someone else inside with her. Eva cheers Croc on by saying "Get 'em baby", she then throws a drink in Robin's face and hits him over the head with something, possibly the glass.
Batman sprays something in Killer Croc's face during their fight which stings him and causes him to flee the building.
Robin then grabs Eva and she is tied up and left for the police to arrest her for abetting a felon.