Waylon Mercy was the perfect example of this. He was friendly to the fans, refs, and even his opponents before and after the matches. He did promos about going to picnics and enjoying summer days. And then he would destroy his opponent in merciless fashion when the match started.
Nick Bockwinkle made a long career of being a polite, well spoken, intelligent, reasonable man who was more than willing to cheat or drop you straight on your head.
Even as Flor De Loto began the twenty seventh year of her career, with a vicious reputation preceded her longer than most of her opponents by that point had even been alive, she never used an offered handshake for a cheap shot, never the first one anyway. She always wanted to give all her opponents a friendly hug.
Tigre Metálico may be a rudo, but is a funny dude who is hardly rude. He plays his own entrance music on a tiny guitar and serenades to children.
WWE's Mankind is a sadistic lunatic in the ring; his early WWF career saw him cast as a dangerous lackey to both faces and heels. On the other hand, his allies found him to be an Extreme Doormat who constantly yearned for affection and praise.
By the skewed standards of ECW, this happened during Cactus Jack's Face–Heel Turn... "Heel" in this case meaning becoming increasingly vocal about the (genuine) concern he had about the (genuine) danger his fellow performers were putting themselves through to appeal to an ever more bloodthirsty crowd. Until he joined up with the more solidly Heel Raven's Nest stable, the worst Cactus would do was to praise WWF and WCW... which naturally got immense heat from the ECW audience.
The Outcast Killahs during their stay in Ring of Honor, despite working for Prince Nana's Embassy which in one way or another ended up interfering with everyone's business. When CM Punk got back from Pro Wrestling Zero 1 and mistook them for Special K, they corrected him and tried to console him over the recent attack on his girlfriend Lucy with a beer(bad idea).
Bobby Fish loves the ROH code and will eagerly greet not only his opponents but the fans, officials and other personnel in attendance. He has trouble complying with the "keep the playing field level", clause however, as he also loves outside interference and sneak attacks. He's also loves to instigate feuds and trick people into harming themselves.
While her open biases and ego do often shine through, Portia Perez is often more carefree, jovial and tolerant than her commentating partner Dave Prazak on SHIMMER's shows, somewhat obscuring the fact she's one of the nastiest pieces of work to work for the promotion. When not commentating she's a pure jerk ass.
Bray Wyatt. Sure he is a cruel, psychotic egomaniac cult leader who fancies himself some kind of primordial force of nature, but he has a good sense of humor, is incredibly polite and is highly charismatic. Plus he's got a really nice singing voice!
The New Day as heels. They never did anything truly evil, not at all. And they bore no ill will toward anyone, unless that person provoked them. They just did whatever they could to win, and were very, very annoying about it.