|Age||Unknown, likely mid-fifties|
|Planet of origin||Amphibios 9, Clan Kroker's Sacred Birthing Grounds|
|Profession||DOOP Fourth Lieutenant|
|Relatives||See Family section|
|First appearance||"Love's Labours Lost in Space" (1ACV04)|
|Voiced by||Maurice LaMarche|
Fourth Lieutenant Kif Kroker is an Amphibiosan working for the Democratic Order of Planets, serving aboard the Nimbus as first officer to Zapp Brannigan. Zapp is generally abusive towards Kif, forcing him to do a variety of demeaning tasks, including shaving his armpits, but Kif meekly tolerates this abuse, as he apparently lacks the confidence to defend himself. However, Kif sometimes seeks out advice from Zapp and is called his most loyal officer and best friend. Since 3003 he has had a relationship with human Amy Wong.
Kif Kroker has fought in wars against the Spheroids of Spheron 1 (2ACV17), the Spiderians of Tarantulon 6 (4ACV16), the Decapodian Army in the Decapodian Invasion of Earth (4ACV05), and in all the Omicronian invasions of Earth (1ACV12, 2ACV15, 6ACV11). However, he was at one point discharged from the DOOP when Zapp Brannigan blamed most of his mistake on him (2ACV02).
Kif also briefly served as first officer on the ill-fated intergalactic cruise ship Titanic, and, even more briefly, as captain of said vessel after Zapp Brannigan abandoned his command leaving Kif to go down with the ship. However, Kif managed to evacuate the ship via the escape pods, which is where he first met Amy Wong.
Kif fell in love with Amy Wong after only a brief meeting with her on the Titanic (1ACV10). For a whole year, he was too nervous to speak to Amy, but eventually admitted his feelings for her (3ACV01). Despite her parents' dislike of him, Amy returned his feelings. Ironically, though, it was them who set Kif and Amy up when Zapp forced the captainship upon him after the vessel crashed. They have been together since their first date (3ACV01).
Hundreds of unnamed children of whom Leela is the mother and Amy is the smizmar when (4ACV01). They are currently living in the the same place where their father was born, in an immature, tadpole form, and will have grown legs and emerged from the water by 3023. Kif's parents live there with them (TBWABB).
 Character Description
Kif Kroker is a nervous and selfconscious individual who suffers from lack of confidence. He is submissive towards Zapp Brannigan, even though Zapp frequently has him do humiliating things. Kif seems like the ideal candidate for General of the DOOP Army, however, he often gets the blame when Zapp makes a mistake and has the credit taken from him by Zapp when he suceeds. However, when under the influence of alcohol, he finds Zapp's statements to be extremely funny.
 Friendships and relationships
 Zapp Brannigan
Zapp Brannigan considers Kif to be his closest friend and most loyal officer, and he even tried to comfort Kif after discovering he was in love with Amy Wong, though with very limited success. Kif has been known to insult Zapp behind his back, and despite being rather submissive towards Zapp, Kif once punched Zapp in the stomach after discovering he and Amy had had a brief sexual relationship (TBWABB).
 Amy Wong
- Main article: Kif-Amy relationship
In 3001, Kif met the Martian engineering student Amy Wong at the Titanic, and exchanges a passionate kiss (1ACV10). In 3003 they developed an intimate relationship (3ACV01), and in 3008 Amy became Kif's fonfon ru (BwaBB). They briefly broke up (6ACV04), but got back together soon afterwords.
- Hundreds of unnamed children, through Turanga Leela.
- Amy Wong, Kif's Fonfon Ru, or wife, and smizmar (see Kif-Amy relationship for more info).
- Mr. and Mrs. Kroker, parents.
- Amy's entire family through Fonfon Rubok.
- At least one sister was briefly seen in "Six Characters in Search of a Story".
Kif is thought to be at least 55 years old, counting his 20 years as a tadpole, his childhood, long enough in the DOOP Army to become a lieutenant, and the 10 years of the show. Part of this is speculation, though.
 Image Gallery
 Additional Info
- Maurice LaMarche stated that Kif's voice is a combination of Jon Lovitz and Truman Capote.
- Kif is featured on one of the discs of The Complete Collection 1999-2009.
- Although Kif is somewhat like an amphibian, he is apparently capable of growing stubble (2ACV02).
- Kif has no bones, but is supported by a system of fluid filled bladders.
- Can walk on walls and ceilings.
- Has three nipples (3ACV01).
- Has a camouflage reflex which turns him almost transparent.
- He loses control of this reflex when he becomes nervous.
- Is actually a highly competent crewman, as evidenced during his brief stint with Planet Express (2ACV02).
- Is a skilled combatant, as he can hit two spiders with a giant double-headed fly swat (4ACV16).
- Is a great karaoke singer, in particular Total Eclipse Of The Heart, due to his time in the DOOP Boys' Chorus.
- Was killed twice and has been ressurected by Yivo (TBWABB) and the birthing machine (6ACV01).
- When he is really sick and/or has a hangover, he actually becomes liquid.
- He is a good yet unusual breakdancer (6ACV08).
- Was shortly promoted to a Captain in the DOOP.
- Kif's most notable word (or in this case, noise) would be his trademark sigh. Usually used when confronted with the ineptitude of his superior, Zapp Brannigan.
Kif: [After holding Amy's hand.] Dear Diary, I just made love for the second time...
Leela: What planet is this anyway?
Zapp: I 'unno. This whole sector is uncharted.
Kif: It is not uncharted, you lost the chart!
Zapp: Show them my medal, Kif.
Kif: [Kif points at a medal on Zapp's chest.] He rented it with his tax refund.
Kif: Use a brush, you dunderhead! And mix these mixed nuts. I see two almonds touching!
Bender: Ow, my arms! I'll never paint again! [He feigns crying.]
Kif: You can't sue the military!
Bender: Oh. I'm alright then.
Amy: But my doctoral exam is in ten minutes! On Mars! [She runs out of bed but steps on something.] Eww! Kif, did you yack on the floor?
Kif: [The green puddle Amy stepped on grows a mouth, it is Kif.] Yes, I did.