I found this on somewhere (can't remember), and I guess I put it here.
Karma Akabane (Semi-Senioritis) - Senioritis is when someone stops caring about school as they approach the end and Karma semi did that.
Yuma Isogai (President Poverty) - Class president and is dirt poor.
Taiga Okajima (Terminal Perv) - The class perv.
Hinata Okano (Amazing Ape) - A gymnast and is easily able to climb things like an ape.
Manami Okuda (Poison Specs) - She wears glasses and is the best at chemistry.
Meg Kataoka (Dignified Didact) - Didact means leader, and she is a leader
Kaede Kayano (Forever Flat) - Running gag that she has a flat chest.
Yukiko Kanzaki (Mistress Kanzaki) - Mistress as in she’s the class idol.
Masayoshi Kimura (Justice) - Justice is his actual name (meaning in Japanese)
Hinano Kurahashi (Fluffy Stag Beetle) - Messed up Okajima’s assassination attempt after Korosensei caught a beetle she was looking for.
Nagisa Shiota (Gender) - Nagisa is a boy that looks like a girl.
Sosuke Sugaya (Lanky Artist) - He is really great at making art and is super tall
Tomohito Sugino (Baseball Geek) - The baseball fan of the class
Kotaro Takebayashi (Glasses) - The only guy in class 3-E that wears glasses.
Ryunosuke Chiba (Dating Sim Protagonist) - Anime protagonists usually have their eyes covered by their hair just like Chiba.
Ryōma Terasaka (Pseudo-Takaoka) - Pseudo means resembles and Terasaka looks like the younger version of Takaoka.
Rio Nakamura (English Lass) - Best at English out of the class.
Kirara Hazama (The Darkness of Class E) - The class emo girl.
Rinka Hayami (Tsundere Sniper) - A tsundere is an anime caricature that matches Hayami and she, along with Chiba, are the snipers of the class.
Sumire Hara (Kunugigaoka's Mom) - Kunugigagaoka is the name of their school and she is the most motherly in the class.
Yuzuki Fuwa (This Manga is Amazing!) - She knows a lot about manga and makes random references throughout the show.
Hiroto Maehara (Womanizing B*stard) - He hits on girls in the class.
Koki Mimura (Mushroom Director) - His haircut resembles a mushroom and he is great with cameras.
Takuya Muramatsu (Loofah) - He has hair that resembles a Loofah sponge.
Toka Yada (Boobs and Scrunchies) - She wears scrunchies and she has a large chest.
Taisei Yoshida (Home Base) - Yoshida’s jawline is shaped like a home base in baseball.
Ritsu (Box O’ Moe) - Moe is another word for cute and Ritsu is literally in a (box?)
Itona Horibe (Picture Book Graduate) - Picture book graduate means someone who just stopped reading books with pictures and since Itona has never been to school, he is one.
Tadaomi Karasuma (Da Densest) - Everyone around him realizes that Irina Jelavic likes him but he doesn’t, making him dense.