Yung Venuz, or Y.V. for short is a purely offensive character with high sustained and burst DPS, but lacks any form of inherent self-defense.
Abilities
Higher Rate of Fire
Y.V. fires all Weapons 20% faster, or to be specific, all Weapons have 20% less reload time. This directly gives him more damage output in exchange for burning through his ammo faster.
Pop Pop
Y.V.'s active allows him to fire two trigger pulls at once, which includes the reload time and Ammo costs as well as the projectile. This is a very useful aspect of his character and can be used for to very quickly eliminate a potential threat. Pop Pop cannot be used on Melee weapons, including those that cost ammo.
Caution should be taken for using Pop Pop as it leaves you vulnerable due to the weapon being on 200% reload time (effectively 160% due to Y.V.'s passive.) The player should also keep in mind that both projectiles fired have their spread calculated differently and one can miss an intended target while the other hits.
Throne Butt causes Pop Pop to fire four trigger pulls at once but extends the reload and ammo cost to be worth three trigger pulls.
This is the only Throne Butt with a direct downside, and how useful you will find it depends on your build and playstyle.
Airhorn
While not a true ability, this is being listed for completion. If you press B on the keyboard while playing Y.V., an airhorn sound will play and the screen will shake. This can also be done when loading into levels and picking Mutations.
Ultra Mutations
Regardless of which Ultra is taken, the player will be transported to Y.V.'s Crib instead of the level the portal would have brought them to.
Ima Gun God
Ima Gun God increases Y.V.'s rate of fire by an additional 100%, for a total of 220% or 2.2. This also directly buffs Pop Pop, as now the reload penalty is significantly lower. Ima Gun God is great particularly for weapons with long reloads, but also works well with ones that already have a high fire rate.
Back 2 Bizniz
Back 2 Bizniz adds an additional free trigger pull to Pop Pop, and adds two additional instead if Throne Butt was taken. This is very ammo efficient and allows high burst damage as opposed to the sustain of Ima Gun God.
As a visual addition, using Pop Pop with Back 2 Bizniz spawns money.
Building
Recommended Mutations
Back Muscle helps Y.V. stay stocked up on Ammo, as he uses a lot of it.
Bolt Marrow is a good choice that compliments Y.V.'s proficiency with Bolt Weapons.
Impact Wrists synergizes with the high knockback Pop Pop deals, especially if Throne Butt and/or Back 2 Bizniz have been taken.
Laser Brain is a direct damage increase to Energy Weapons, which further increases Y.V.'s already high damage output.
Long Arms pairs well with Y.V.'s faster fire rate in destroying projectiles.
Lucky Shot can provide Y.V. with another source of extra Ammo, especially on large groups of enemies.
Open Mind can provide an additional Ammo Chest for Y.V., though this should not be relied upon and there are better sources of Ammo.
Rabbit Paw ensures Y.V. gets enough Ammo.
Recycle Gland can allow Y.V. to fire Bullet Weapons for even longer.
Scarier Face creates additional breakpoints Y.V. can achieve with Pop Pop and ensures he doesn't have to spend as much Ammo.
Stress further increases Y.V.'s fire rate. While it is fairly low priority as him due to Ima Gun God being superior, nothing will stop you from stacking them besides the Ammo drops.
Trigger Fingers helps mitigate the extra reload time from Pop Pop.
Not Recommended Mutations
Eagle Eyes is best avoided.
Shotgun Shoulders still does little to boost Shell Weapons, even for a gun god.
Changes in Mods
NT:TE
When interacting with Cat Chests, Y.V. may have the option to select a Coat instead of any other Pickups offered. This unlocks the skin of the same name and removes that option permanently.
Outside of co-op, Y.V. has exclusive access to the Cuz "Pet." Pressing B while Cuz is with you will cause him to cheer alongside the airhorn.
Trivia
Y.V. is part of the 3 Mutants added in the transition from Wasteland Kings to Nuclear Throne.
Y.V. is from Vlambeers previous game, Gun Godz. Unlike in Nuclear Throne where he is playable, Y.V. is the main antagonist of Gun Godz.
Y.V. is a Gun God from Venus, who also has a successful rap career.
Y.V. is voiced by Doseone, and speaks Venusian instead of Trashtalk. He also beatboxes.
Y.V. is heard collaborating with an unseen Venusian named Moist Mother or M.M. for short.
Y.V.'s cousin, Y.C. was originally planned as a playable character. His assets were turned into a C Skin for Y.V. in Nuclear Throne Together, and the character has since been recreated in a standalone mod.
JW has confirmed that Y.V. is not young, and "Yung" is simply his rapper name.
Y.V.'s favorite indie game is Cave Story.
Y.V.'s exploits outside of the games include buying a bank to turn it into a club, going to Vietnam, and shooting people that ask questions or call him weird.
Y.V. sees reaching the Throne as a fun challenge instead of a struggle for survival. This is why he plays on the same grounds as the other characters, and why he simply teleports home when depleting his "health."
Y.V. is similar to the Eye of Providence, or what it's commonly viewed as, the Illuminati.
Y.V. has a bubble when underwater despite not needing to breathe. JW has stated that this is so his money stays dry.
Y.V. is bilingual, being able to speak both Venusian and clear English. When not rapping however he seems to use shortened versions of words, such as "mony" instead of "money," "2" instead of "to" and "str8" instead of "straight."
Y.V. is seen on vending machines in Frozen City.
Y.V. is presumably the owner of the Golden Weapons.
Y.V. and Pop Pop are usable cards in The Binding of Isaac: Four Souls.