To be incredibly good at something.
Billy: Did you see Jill run the 100m sprint?
Bob: Yeah, she's so tankus, she beat everyone by like 5 seconds!
A living example of inter-species breeding.
One such case currently resides in Canada. While the guesses as to which species it was run close to infinite, most scientists suspect he was conceived during a wild party involving a herd of buffalo and his crack-addicted mother.
Christ, you tankus... They really ruined a perfectly good rectum when they put teeth in your mouth.