The Archer: Subverted. In Skyrim, he often tries to take sneaky shots at opponents, but sucks at it because of bad aim, bad luck and more importantly, the fact that he has barely leveled his archery skill and plays in high difficulties.
An Axe to Grind: When he started playing Skyrim, it didn't take much time before he chose battleaxes as his favorite type of weapon, although he uses two-handed swords more often as of now.
Badass Longcoat: Bob himself wears a red, royal knight/pirate-like one when he shows up at conventions where he holds panels, and gave the same kind of outfit to his Minecraft avatar.
Berserk Button: He really doesn't like The Empire in his Skyrim playthrough, so when the Riverwood Bard's song Bob jusk asked him to sing, turns out to be about the Imperials... Bob's reactions is quite explosive.
BFS: With his various mods, he manages to craft himself Conan's very sword, and doesn't hesitate to use it, even though Battleaxes are still his favorite weapons.
Blatant Lies: In-Universe. During a quest, he dismantle a skooma cartel, and then take all the drugs (in order to offer them to Kharjo). Then he makes his report to the jarl:
Jarl: Did you find anything interesting in this warehouse?
Bob: I discovered skooma's root. Unfortunately, impossible to find a single drop. Everything was gone, including the 59,4 kg of moon sugar. Weird. Strange.
Blood Knight: He has tendencies to just kill everything around him when provoked, even his own allies during missions along the Stormcloaks.
"Hi, I'm Bob Lennon! Haha!": Opening catchphrase he says everytime he appears in any video. Affectionate Parody of Troy McLure (he even used to say after this "You may remember me from [silly title X] and [silly title Y].").
"Grudu": Doesn't mean anything in particularnote though it is the name of the completely insane barbarian bodyguard in Kaamelott, but is frequently used as some kind of grunt whenever his character is just acting tough. Or sometimes as a substitute to "Hello".
"Cuir, cuir, cuir, moustache!" (Leather, leather, leather, mustache): Used everything anything exceedingly manly happens, especially if it has homosexual overtones, such as, well, a manly man wearing leather. Currently replaced by a running gag about pinching one's nipples for "ninja training".
Content Warnings: Bob is partially known for his attitude involving a lot of swearing. He has receive some complaints from mothers about it, but answers that it is their responsability to control what their children are watching, highlighting that he is partly playing M-rated games.
But he likes and respect his younger audiance, and states this is why he will never play really scary games on his channel, like the Fatal Frame franchise.
Cuteness Proximity: His fondness for cats makes him d'aaaaw and squee all over the place whenever he sees Khajiits. When Kharjo is his companion, he occasionally notes how cute he is, even when wearing heavy armor, a sword and a shield.
He eventually loses it when he comes across a Khajiit orphan, courtesy of a mod.
Death from Above: Call Lightning and Meteor, two mod spells he uses in the 300th special where he goes through the entire Mage Guild. Accordingly, they only work when he's outside.
Also used to scare Biloulette when she plays Amnesia.
Failed a Spot Check: In the first episodes of the Playthrough, Bob seems to miss or downright ignore a lot details, leading him to die a few stupid deaths, get lost when the right path was right in front of his face, or taking an immense amount of time looking for clues everywhere for a puzzle, when he's got a book that basically tells him what to do.
Nowadays, he still seems unable to grasp how the on-screen compass/radar works. He has no trouble noticing the red dots indicating enemies, but he apparently cannot see the destination markers, often running a few hundred meters in what he believes to be the right direction, while the marker isn't even remotely close to the center.
Flaming Skulls: One of the mod spells he uses in the 300th special, where he does the entire Winterhold Mage Academy's questline; allows him to throw exploding, burning skulls everywhere.
Full-Frontal Assault: Mostly in Tenchu Z, but also in Skyrim and Saints Row III (in fact everytime there is a Character Customization menu). He call himself in these occasions the "Nudist Ninja", stating that a real ninja doesn't need any clothes (because nobody can see him) and it also is the supreme humiliation for his opponents.
"Just imagine you're a guard, and you know there's a deadly ninja assassin who's coming for you. You hear a sound behind you, you turn back... nothing. But you know he's there somewhere, and you heard the rumor this guy is a nudist, but you can't verify it. And the only way you could discover the truth is the time your decapitated head rolling on the ground sees him, and your final though is 'My God! It really was a nudist'."
He also likes to invent the meaning of the BSAA acronym, which usually results with something like "Bullshit Super Augmentée Artificiellement" (Super Artificially Increased Bullshit, which make reference to Chris's sudden musculature).
Game Mod: He mods his game quite a lot, even though he initally promised to play it normally, in order to show what the game actually is like to people who don't have it. His game is currently heavily modded graphically, has various tweaks and contains a lot more items than normal.
Glass Cannon: His love for "barbarian" armor, as in fur and leather, makes him very vulnerable since these are some of the weakest types of armor. He still carries a big axe and likes to cast fire spells around.
Gratuitous English: By inserting English words in his French phrases, such as "full", "bullshit" and "doom". He has a decent English level, being able to have a perfectly understandable conversation with other English speakers, but sometimes uses it a bit off context.
Lampshaded many times, especially when they improvise Romulo and Juliano, a Romeo and Juliet gay parody imagined by Bob when visiting Kigyar69's server theater.
Ironic Echo: A lot of his subscribers note how he initially said he would just do the main quest and be over with it, but is still exploring all the secondary questlines even at the 150 episodes mark.
Imaginary Friend: The Skull, a silly poltergeist who makes fun of Bob during his Skyrim playthrough.
"KAKAKAKA!! Hi Lennon! I'm here, Lennon!"
Kid Sidekick: Nanette, a.k.a Mini-Lennon, his 13 years old sister in law.
Kindhearted Cat Lover: Bob has two cats IRL, named Poupette and Wilfrid. His fondness for Poupette also create the term "poupet" he uses to designate cat-like creatures in video games, like khajits. Also see Cuteness Proximity.
His immoderate love for cats makes him more forgiving toward them, sometime even sparing enemy khajits.
Make Me Wanna Shout: Of course, considering the game he's playing. That and all the mods he installed to change/enhance his shouts. He has a great tendency to Fus Ro Dah people away when they annoy him and he can't afford to go on a killing spree. In his latest episodes, he made the Fus Ro Dah ridiculously powerful and can pretty much scream his victims into orbit when there isn't a ceiling in the way. Becomes hilarious when he blasts Kodlak Whitemane into the sky for criticising his sword, and sees him pinball out of sight when hitting the border of the skybox.
Ninja: He tries to be one during the whole five and a half hours of his 200th episode special, since he spends the entire session going throught the Dark Brotherhood's questline. He isn't exactly good at being sneaky, but still manages some antics with his gear mods and overpowered enchantments, effectively turning him into a poor man's (and hilarious) Ryu Hayabusa.
Ninja Pirate Zombie Robot: Dwemer Mechanical Dragons and Ghost Dwarves (well, Dwemers), courtesy to mods, and seen in their full threatening glory in the 300th special, especially when three mech dragons attack Bob when he tries to find the entrance of a Dwemer dungeon.
Playing with Fire: While his character is not exactly a mage, he's still a Pyro-Barbarian. His magic generally sucks against anything else than low-level bandits or wild animals, tough.
Power Armor: The "Plan B", a modded Dwemer armor set with overpowered enchantments, complete with steam exhausts and a 'steampunk electric shotgun'. Bob uses it in the 300th special when his magic isn't enough to get him through a horde of powerful modded enemies in Dwemer Ruins.
Rapid-Fire Comedy: He makes an almost unending chain of over the top reactions, warcries and improvised jokes about the game.
Rapid Fire No: During Leon's campaign in Resident Evil 6, Bob (as Helena) got caught by a monster who tried to push him in a grinder. After an epic QTE battle, he fight off the monster, but did not expect a second QTE. Bloody ending ensues.
Robosexual: Tends to spend a lot of time seducing CID in Saints Row IV. In fact, he pretty much has a go with him every time he gets back on the ship, and has been serviced by him much more often than all the other romanceable characters put together.
Robot Me: Bot Lennon, a robotic version of himself used in a trailer for the Minefield server.
The Scrappy: Calder, In-Universe. He really doesn't like this guy and never really gave him a chance to be useful, only taking him along once for fun, as well as Lydia and Kharjo, courtesy of a mod allowing him to have more than one ally at a time. Nowadays, he just sits in his home at Lakeview Manor, posing as a robot butler in Dwemer Armor renamed C4LD3R Unit.
Take a Third Option: During the quest "In My Time of Need", the player has to side with Saadia or with the Alik'rs, with no clues of who is telling the truth. Bob kills both Saadia and Kematu (the Alik'r's leader).
This caused a bug which makes remain the two Alik'r warriors which gave the quest to Bob. They particularly annoy him, who cannot kill them without alerting the guards.
"The horker lives in his environnment of choice: the ice. Sometimes, you can see it wallow into dung, seeking for remains of brave adventurers who perished for his meal. Occasionally, you can meet a flying fire salamander in this land of ice. [...] We decided to name her Sandra. Sandra is one and half month pregnant; she will soon give birth to her children. [...]
That's the kind of stuff you watch late on Arte when you're drunk or dizzy. 'Oh! The Salamander is in labour! Her child is nammed Kevin!'."
He also sometimes comment his own actions like if someone was making a documentary about a "wild Bob Lennon" or a "wild kikoo".
"'Ololol!' - The kikoo just finds a prey. He could eventually reproduce. - 'TROLL! 4chan! Reddit! Ololol!'."
Would Hit a Girl: Since female opponents are pretty much as frequent as men, he doesn't really care. But he also has no qualms about Fus Ro Dah-ing his wife.
Wrestler in All of Us: Since he made weaponless combat more reliable with the help of mods, and also made executions more frequent, he takes great pleasure in bodyslamming/german suplexing fools.
Wrongfully Attributed: Bob is oftenly quoting some of his favorite Internet celebrities, including StateAlchemist, creator of Saint Seiya Abridged. But being now more popular than this abridged series, some of the quotes and voice impersonations he does are attributed to him, even causing some ignorants Bob fans to accuse StateAlchemist of plagiarism. But State is not mad at Bob for this, and even made a special video for his anniversary.
"No! Not the infernal and filled with germs depths of oblivion!"