The killstreak menu.
Killstreaks
From the Hypixel Pit Wiki

A killstreak is a term used in The Pit to refer to two or more kills earned in a row without dying. A player's killstreak is visible on their sidebar. Earning a killstreak of six or higher has a chance to grant the player a bounty; this bounty will continuously increase as the player's killstreak grows.

Killstreak perks are purchaseable at the Upgrades NPC. These grant the user a reward that triggers every time they obtain a certain multiple of kills. Additionally, earning fifty kills, in most cases, triggers a megastreak – a status that grants the user rewards as long as the streak is active.
When players reach level 10, they receive one killstreak slot, granting the player the ability to use one killstreak perk. A second killstreak slot is unlocked at prestige I (level 75), and a third can be purchased in the renown shop at prestige IV for 50 renown, unlocked at level 100. Players start out with eight killstreaks. Additional killstreaks can be purchased in the Killstreak Bundles section in the renown shop.

Killstreak perks, their requirements, and details are shown below:

NameCostReqs.Description
Second Gapple1,500gEvery 3 kills / [10]Add 5 XP and 5g to the kill or assist that activated this killstreak, and receive a Golden Apple.
Explicious3,000gEvery 3 kills / [20]Add 12 XP to the base XP of the kill or assist that activated this killstreak.
Arquebusier5,000gEvery 3 kills / [50]Add 7g to the base gold of the kill or assist that activated this killstreak, 16 arrows, and Speed I (0:10).
Fight or Flight5,000gEvery 5 kills / [50]If the user is under half health, gain Speed I (0:07) and Resistance I (0:07). Otherwise, deal +20% damage for 7 seconds.
Hero's Haste15,000gEvery 5 kills / [100]Gain Speed II (0:05).
Feast4,000gEvery 7 kills / [30]Obtain an AAA-Rated Steak (raw mutton). Steaks are eaten instantly, granting a 20% damage boost, Speed I (0:10) and Resistance I (0:10).
Counter-Strike5,000gEvery 7 kills / [40]Deal +15% damage and block 1♥︎ per hit for 8 seconds.
Spongesteve12,000gEvery 25 kills / [70]Gain 15♥︎ of Absorption.
Overdrive FreeTriggers on 50 killsMain article: Overdrive


NameFound inGold CostReqs.Description
R&RBeastmode Bundle (III, 10 renown)4,000gEvery 3 kills / [40]Gain Resistance I (0:03) and Regeneration II (0:03).
Tough SkinBeastmode Bundle (III, 10 renown)3,000gEvery 5 kills / [30]Receive −3% damage; stacks up to −24% (40 kills).
Tactical RetreatBeastmode Bundle (III, 10 renown)5,000gEvery 7 kills / [50]Gain Regeneration IV (0:05) and Weakness IV (0:05).
MonsterBeastmode Bundle (III, 10 renown)10,000gEvery 25 kills / [40]Gain an extra max ♥︎. Max of 2 (50 kills).
BeastmodeBeastmode Bundle (III, 10 renown)10,000gTriggers on 50 kills / [30]Main article: Beastmode
PungentHermit Bundle (IV, 20 renown)5,000gEvery 7 kills / [50]Gain a smelly bomb that applies Slowness I (0:04[bug]In-game description states 5 seconds.) to players within 3 blocks.
Glass PickaxeHermit Bundle (IV, 20 renown)6,000gEvery 7 kills / [60]Gain a single-use diamond pickaxe that deals +4.25♥︎ damage and 0.5♥︎ true damage.
Aura of ProtectionHermit Bundle (IV, 20 renown)8,000gEvery 10 kills / [50]Gain an Aura of Protection spell item granting Resistance II (0:04) and True Damage immunity for 15 seconds.
Ice CubeHermit Bundle (IV, 20 renown)9,000gEvery 10 kills / [60]Gain an Ice Cube item. The Ice Cube is single-use on a melee strike, dealing 1♥︎ of true damage to the target. Applies Slowness I (0:10). Gain 40 XP on use.
HermitHermit Bundle (IV, 20 renown)20,000gTriggers on 50 kills / [50]Main article: Hermit
KhanateHighlander Bundle (VII, 40 renown)6,000gEvery 3 kills / [60]Stack +4% damage against bountied players. Maxes at +40% (30 kills). Does not grant any gold, despite description.[bug]Khanate is intended to grant 8g to the kill or assist that activated this killstreak.
RushHighlander Bundle (VII, 40 renown)25,000gEvery 5 kills / [110]Gain 1.5% speed. Maxes out at +15% speed (50 kills). Overridden by Gotta go fast.
Gold Nano-factoryHighlander Bundle (VII, 40 renown)6,000gEvery 7 kills / [50]Obtain a molecular assembler (gold nugget) that spawns 7 gold ingots when right-clicked. Gain Regeneration IV (0:02) on use.
HighlanderHighlander Bundle (VII, 40 renown)30,000gTriggers on 50 kills / [60]Main article: Highlander
LeechMagnum Opus Bundle (X, 60 renown)6,000gEvery 3 kills / [70]The user's next hit heals for 0.5♥︎ + 20% of its damage.
Assured StrikeMagnum Opus Bundle (X, 60 renown)10,000gEvery 7 kills / [80]The player's next melee hit deals +35% damage and grants Speed I (0:20).
Apostle to RNGesusMagnum Opus Bundle (X, 60 renown)50,000gEvery 25 kills / [100] A random number from 1 to 100 is selected. Based on the number, some of the following effects may occur.
Multiple of 2: Gain Regneration I (0:20).
Multiple of 3: Gain Speed I (0:15).
Multiple of 4: Gain Regeneration II (0:10).
Multiple of 7: Gain between 500–5,000 gold.
Multiple of 8: Gain between 500–5,000 XP.
Multiple of 12: Gain 4♥︎ absorption.
Multiple of 13: Deal +25% damage for 30 seconds.
27 or 43: Gain 1 renown.
13 or 66: Gain 3 Chunks of Vile.
77 or 88: Gain a Mystic Sword, Mystic Bow, or a standard color of Fresh Pants.
42: Gain 10♥︎ of absorption.
50: Gain an RNGesus Helmet (diamond helmet).
99: Get struck by lightning for 4♥︎ of true damage.
Magnum OpusMagnum Opus Bundle (X, 60 renown)40,000gTriggers on 50 kills / [70]Main article: Magnum Opus
Super StreakerTo The Moon Bundle (XIV, 150 renown)20,000gEvery 10 kills / [80]Add 50 base XP to the kill or assist that activated this streak. Stack a buff of +5% XP and +5% max XP from kills. Maximum of +50%. Buff resets if the streak is reset or the Spire event ends.
Gold StackTo The Moon Bundle (XIV, 150 renown)25,000gEvery 10 kills / [90]Permanently gain +0.1g per kill. Resets on prestige. This bonus maxes out at 0.5g with an additional maximum of 0.1g per prestige. The gold bonus applies even when the killstreak is not active.
XP StackTo The Moon Bundle (XIV, 150 renown)25,000gEvery 10 kills / [90]Permanently gain +0.05 XP per kill. Resets on prestige. This bonus maxes out at 1 XP with an additional maximum of 0.2 XP per prestige. The XP bonus applies even when the killstreak is not active.
To The MoonTo The Moon Bundle (XIV, 150 renown)50,000gTriggers on 100 kills / [80]Main article: To the Moon
UberstreakUberstreak (XX, 50 renown)50,000gTriggers on 100 kills / [90]Main article: Uberstreak

Trivia

Dying three times in a row without getting a kill triggers a Death Streak, where a player receives the item they get on kill.

Killstreaks were added in The Pit Update 1.0.0 - Release.