Though Friends had a core group of six, many one-off and recurring characters came and went during the course of their lives. Some of those characters were positive additions to the series when they showed up; they added to the storylines, characters' relationships, and comedy. They also offered insight to some of the main six and sometimes opened up a path that some characters could have explored. Maybe they added a family element that was sorely missing before their introduction, or maybe, they were a positive influence on one of the six, either romantically or platonically.

However, that wasn't the case with all of the new characters added to the series throughout the years as some had a negative effect on the series as a whole. Some made certain characters of the main six look questionable, whether it was what that character added or how one of the main bunch behaved as a result of their presence. In some cases, these characters weren't bad at all. In fact, if not for their effect on one or more of the main characters, maybe they would've been good to keep around. In at least one case, someone positively influenced one of the main characters, but led to negative reactions from another because of it. With that being said, here are 15 New Character Additions That Hurt Friends (And 10 That Saved It).

Hurt: Danny

Rachel briefly dated Danny when she was trying to move on from Ross in season 5. Moving on was the right move, as Ross and Emily had just gotten married, even though he said Rachel's name. Danny's first appearance was fine. He called Rachel out for judging his shaggy appearance, but after that, the character and plots connected to him went downhill.

After Danny didn't call her back, Rachel decided he was playing games and turned the tables on him. Then, after they did go out, she met his sister, with whom he had a relationship that seemed inappropriate. It was weird, and there didn't seem to be any point to it.

Saved: Estelle

A scene with Estelle usually meant plenty of laughs. She might not have been the best agent that Joey could have gotten, but Joey wasn't the best actor. Since this was a comedy, her mistake in thinking Joey fired her and sabotaging his career as a result was played as a joke.

Friends needed a character like her who provided comedic moments. Her scenes were entertaining, she was favorable, and she never dated any of Joey's friends. The show even benefited from Estelle after she passed away. Because so much was changing, Phoebe decided to impersonate her and keep that bit of information from Joey. Though he eventually found out, fans still got a few laughs from that scenario.

Hurt: Janine

One of the problems with Janine is how she made Joey look. He chose her as a roommate solely based on her looks and knew nothing about her. While that wasn't surprising from Joey, it was just plain odd. If he had just dated her based on that information, fine, but he lived with her.

Furthermore, she didn't treat Monica and Chandler very well, and had no problem telling Joey she didn't like them. Who doesn’t like Monica and Chandler? Sure, they have their quirks, but her dislike of those quirks seemed a bit much.

Hurt: Leonard Green

Rachel's father had his moments. He was entertaining when Rachel and the others tried to keep him and her mother apart on her birthday, and watching his scenes with Ross was fun as well since they only got along when it came to making fun of Rachel.

However, his reaction to Rachel's pregnancy was a low point. Rachel lied and said Ross wouldn't marry her, so naturally, Leonard confronted him. But while doing so, he insulted Mona, an innocent bystander. For the most part, Leonard was very impolite, mostly to those who didn't deserve it, especially that waiter.

Saved: Richard

Richard might have tried to get in between Monica and Chandler, but he was generally a good character. Despite the fact that he was Monica's father's friend, he and Monica had a mature and significant relationship. Amidst the Ross and Rachel drama, and some other temporary love interests, he wasn't the worst by any means.

Instead, he managed to spend time with the others, despite the awkwardness of his friendship with Joey and Chandler. Later on in the series, he and Monica ended their relationship when it became clear they wanted different things (i.e. children). He was a good guy, and he stepped back when he knew he should.

Hurt: Mark

On the one hand, Mark helped Rachel get two great new jobs. He arguably did more for her career-wise than any other person who wasn't named Rachel.

However, he was also responsible for Ross' jealousy, and everyone knows how that turned out. It wasn't attractive in season 3 when Rachel and Ross were dating, and it was just as bad in season 10 when they weren't. Although none of this was Mark's fault, he was entangled in the Ross and Rachel drama so thoroughly that the perception of his character suffered for it.

Saved: Frank Buffay, Jr.

Perhaps the best thing about Frank Buffay, Jr. was that he was a family member who wasn't just forgotten. Despite not appearing after the 100th episode in season 5, he returned in season 10 to offer an update on his and his family's lives. Outside of Frank, there were some family members (i.e. Ben) who just disappeared in the later seasons, with no explanation.

Beyond that, it was nice to see Phoebe have someone from her family in her life. Even though her twin sister appeared during significant times during that span, Phoebe and Ursula were never close.

Hurt: Joanna

It's hard to decide what was worse about Joanna: her professional life or her personal one. On the one hand, Chandler is mostly to blame for the latter, but she was quite persistent.

She also weakened Rachel's attempt at a promotion at work, and though she agreed to fix it, she lost her life before she could. That also didn't negate what she had done and how she made Rachel look in front of the hiring committee. Joanna was only in three episodes, but she was memorable (not in a good way) for each of them.

Hurt: Bonnie

Although there was nothing wrong with Bonnie herself, she was part of a weak storyline. So, it would've been better if she had never existed on the show.

For starters, Rachel only agreed to let Ross date her because she thought she was (still) bald. Then, Rachel, who broke up with Ross for being with someone else, was with him while he was still with Bonnie. She didn't even want him to break up with Bonnie that night. Under these circumstances, adding Bonnie ended up making Rachel look even worse than she already did, which wasn't even her fault. Any character that would've been put in that position would've resulted in the same outcome.

Saved: Erica

On the one hand, “The One With the Birth Mother” featured an adoption agency that mixed up files (a big mistake). On the other hand, it introduced Erica, an entertaining and funny character who chose Monica and Chandler to be the parents of her baby.

It was Erica's presence and the mix-up at the agency that led to Chandler's great speech about Monica already being a mother. And, of course, her continuous misinterpretations, like whose heartbeats the doctor was referring to, led to some laughs as well.

Hurt: Emily

Oh, Emily. She really got the short end of the stick. In season 4, she was fine, then came season 5. While Ross was in the wrong for saying Rachel's name at their wedding, it was Emily who came across as the bad guy. She gave Ross unreasonable demands if they were to continue their marriage and she wanted to know where he was at all times.

If Emily had remained like she was before their wedding, maybe she wouldn't have made this list. However, because the series was all about Ross and Rachel, her character and viewers took a hit.

Saved: Theodore and Bitsy Hannigan

Mike's parents might have been impolite and dismissive of Phoebe as their son's girlfriend, but they were funny. They were a great way to get an outside perspective on Phoebe, especially since by that time, fans were used to the wild parts of her past.

They were also only around as much as they needed to be: to meet Phoebe, be at the rehearsal dinner, and the wedding. Every character didn't automatically have to love the main group of characters, and it was refreshing when some didn't, which was the case with Theodore and Bitsy Hannigan.

Hurt: Tag

Remember when Rachel hired an assistant based on his looks? They briefly dated and then broke up because they were at different places in their lives.

He briefly reappeared, long enough to be considered a possible candidate for the father of Rachel's baby. But after finding out she was pregnant, it was enough to change his mind about wanting to get back together. Tag was fine for the role he filled, which was a temporary love interest. However, he was also quite bland and never really added to the show. Instead, Rachel, who made several significant strides in her career over the series, looked silly when she hired him.

Hurt: Amy

Amy was not a nice person at all. She couldn't even remember who the father of her sister's baby was. Whereas some characters do learn and grow into better people on TV shows, Amy never did.

She was the same person both times she appeared rather than developing just a bit. Like Jill, she showed how much Rachel changed from the pilot, but one episode was more than enough for her.  Friends might have been better off just telling viewers about Amy because she didn't seem to add to the story, and the comedy could've come from elsewhere in those episodes.

Saved: Sandra Green

Rachel's mother had her moments. But perhaps the best part about her was showing how much Rachel had grown, but still had a lot to learn. This was evident when it came time for Rachel to know how to raise her child. She even volunteered to move in with Rachel to help out and teach her daughter the proper care.

Alternatively, the series wisely kept her and Rachel's father separate, considering they probably would have been difficult together. Sandra also offered a look at the life Rachel might have had if she didn't run out on her wedding day and actually married Barry.

Hurt: Eddie

Eddie was quite the character. He might have had his issues, but what Chandler and Joey did to him wasn't right. He refused to move out, so they moved his stuff out, put Joey's in, and told Eddie he never lived there. Somehow, he believed them.

Was it necessary for Chandler to have a roommate after Joey moved out? Maybe. Was it necessary for that person to be Eddie, a character fans would be happy to see go? No. Fans were never going to like whoever lived with Chandler because they weren't Joey. However, that roommate didn't have to be someone who was creepy and unpredictable like Eddie.

Saved: Phoebe Abbott

The introduction of Phoebe Abbott brought with it the truth about Phoebe Buffay's biological parents. Really, after everything that was said about her family and past, Phoebe deserved to have family in her life.

Phoebe Abbott came in at the right time for Phoebe as well. Her brother and his wife wanted her to be their surrogate and no one else could have offered a perspective on carrying a baby and not raising it. And no one except someone just like Phoebe would've used a puppy to demonstrate that. The only problem with her character is that she wasn't around more.

Hurt: Chloe

You might not remember Chloe by name, but you're sure to remember “we were on a break.” She was the girl from the Xerox store Ross was with just hours after he and Rachel took “a break.”

While Ross was clearly in the wrong, Chloe was no angel either. She didn't care about loyalty and often took things from the men she was with. No matter how you feel about Ross and Rachel, she's always going to be the girl who broke them up. Is that fair? No. However, that's her only real association with the show.

Hurt: Pete

The problem with Pete wasn't his feelings for Monica, that he decided to become an ultimate fighting champion, or that he didn't care about how he spent his money. It wasn't even his relationship with Monica. It was how Monica looked because of him.

She did a complete 180 when it came to her feelings. Not only did she decide that she did like him, but they said “I love you” pretty much immediately. Then, after she broke up with him, that was it. She didn't seem to mourn the end of the relationship at all.

Saved: Emma

Emma was a significant part of Rachel and Ross' relationship, even if they weren't together. She was one of the few good things to come out of Ross and Rachel's emotional rollercoaster.

Since Ben seemingly disappeared from existence, Emma offered the opportunity to see the characters as parents. They couldn't just send her off-screen to another parent all the time because both of her parents were main characters. Fans also saw different sides of others like Joey and Chandler, in relation to caring for and about a baby. She played a significant part of these characters growing up.