Dr. Kahl's Robot is a huge machine. The robot has a hatch in it's head where Dr. Kahl controls it. It has two openings on its abdomen, as well as an antenna that fires large lasers. The robot also has many lights on its head and sides. it also appears to be capable of consuming bubble gum as evident by the intro sequence. Dr. Kahl himself looks like a typical mad scientist, wearing large glasses, a lab coat, and bearing a purple beard and mustache.
The robot has no real personality, being a robot. However, it is capable of expressing emotion, as it makes an agitated expression when its antenna is destroyed, and a confident expression prior to this.
Dr. Kahl himself has the personality of a stereotypical mad scientist, cackling at Cuphead and Mugman as the remains of his robot attack Cuphead and Mugman. he also appears to be an incredibly skilled inventor, being the robot's creator.
Before the battle, Dr. Kahl wiggles his eyebrows repeatedly before heading back into his robot, who blows a piece of bubblegum.
"OBJECTIVE COMPLETED. TARGET SCRAPPED."
—Dr. Kahl's Robot, Phase 1 Death screen
- Laser Beam: The antenna on the robot's head targets Cuphead (or Mugman, before switching again to Cuphead) with a tracer laser that then expands drastically after a short moment. The laser will destroy any attacks that cross its path aside from the EX missile attack. In Simple and Expert mode, it will not fire from the start for a very long time.
Hitpoints = 250/150/180
- Laser Bot: A pink cylindrical bot is released out of the chest that fires a laser vertically across the screen. The attack is unavoidable, and players need to parry the bot to cancel it. In Simple mode, it moves slower across the screen. In Expert mode, it moves faster.
Hitpoints = 250/150/180
- Boterangs: Four small boomerang-like robots fly out of a the robot's abdomen, which progress from top to bottom in a zigzag pattern. These can be destroyed in a few attacks. In Simple mode, it just spawn two robots with a large interval between those. In Expert mode, those robots moves faster.
Hitpoints = 250/150/180
By destroying the places these attacks come from, the robot will gain three new attacks depending on which place was destroyed:
- Head Cannon: After destroying the antenna, the robot becomes angry, and tilts the upper portion of his head backwards to expose his cannon, which fires nuts and bolts in a spread shot of five or six scraps. In Simple mode, the scraps travel slower and only comes in fours and fives. In Expert mode, they travel faster and the rate of shooting increases.
- Robotic Arms: After destroying the robot's chest, the robot will begin to use its arms for attacking. It can either hold up a magnet in the lower left portion of the screen that pulls the players towards it, or it can send its twisting arms through the middle of the screen, which fire out bullets vertically upon retracting. In Simple mode, only the magnet will appear.
- Homing Bombs: After the abdomen of the robot is destroyed, homing bombs are periodically released from the damaged abdomen, chasing the players until they are destroyed or they collide with another bomb. The bombs explode in a large radius in the shape of Dr Kahl's head that lasts a short while. In Simple mode, the speed of the bomb slightly decreased. In Expert mode, the speed of the bomb increased dramatically.
After destroying all 3 parts, a heart will be revealed from the robot's chest, when it taken enough damage, it will have a black smudge on half of the heart. When the heart is destroyed, it will cause the robot to malfunction and shoot off what appears to be an escape pod, which commences the second phase of the battle. However, in simple difficulty even the head-ejecting mechanism will seem to malfunction, ending the battle.
Hitpoints = 500/225/300
—Dr. Kahl's Robot, Phase 2 Death screen
In this phase, the robot's head continuously charges back and forth from off screen to damage the players if they inadvertently run into it. Each time it passes on the screen, it will bring a Homing Bomb from the prior phase with it to damage the players. In Expert mode, the speed of the head and bombs increases.
After taking enough hits, the robot will stop, and open its eyes, as Dr. Kahl reveals himself and begins the final phase of the battle. Hitpoints = 280/360
"I have the perfect equation to hinder yer evasion!"
—Dr. Kahl, Final Phase death screen
In the final phase, Dr. Kahl's primary attack is pulling out either a red or blue gem, which fires radial bursts in either a clockwise or counterclockwise rotation, with some shards parryable. The blue gem will fire in burst of six and the red one will fire eight. In Expert mode, the bursts are fired at a higher rate, the blue gem will fire in a burst of five and the red one will still fire eight but with a more irregular pattern.
Not only do the players have to dodge Dr. Kahl's attack, but also the electrified walls that occasionally appear, moving in from the top or bottom of the screen, moving down or up respectively, eventually they will completely close off and leave the player no chance to escape. The mini-plane is very useful for this phase, as switching in and out of it can help dodge the attacks. In Expert mode, they appear more often.
Once players pull enough damage, the robot's head vents its exhaust, and Dr. Kahl is now inexplicably shown naked and dazed, the robot is too damaged to continue. Hitpoints = 1120/1440
|Dr. Kahl and his robot's introduction.|
|The robot laughing.|
|The robot's antenna breaks.|
|The robot's lower chest breaks.|
|The robot's upper chest breaks.|
|The robot's heart springs out.|
|The robot's heart breaks.|
|Dr. Kahl popping out from his robot's mobile head.|
|Dr. Kahl using the diamond.|
|Normal Mode||Expert Mode|
- Neither Dr. Kahl nor his robot appeared in the good ending.
- Dr. Kahl's Robot is the only boss that loses two phases in Simple mode.
- There is glitch where if the Mini-Bomb EX attack is used on the robot in Phase 1, the battle will not continue to Phase 2 and 3 for the remainder of the battle.
- The player can still defeat Dr. Kahl's Robot, but it will take more time to defeat him and when he is knocked out, it would show him as he would appear in Phase 3, but sideways.
- An error on the Phase 3 death screen depicts Dr. Kahl's glasses as yellow instead of green.
- The boss' design pulls off of various other media, the first phase appears similar to the Iron Giant from The Iron Giant, Bender from Futurama, the Tin Man from The Wizard of Oz or the title machines from the Superman short The Mechanical Monsters. Dr. Kahl's mode of transportation in the final phase is reminiscent of Bowser's Koopa Clown Car, Dr. Eggman’s Egg Mobile or possibly Dr. Wily's Wily Capsule.
- The first phase of the fight seems to bear a strong resemblance to the battle with N. Gin from Crash Bandicoot: Warped.
- The battle seems to take inspiration from the cover of the book The Iron Man.
- The Laser Bots that the robot sends have a similar design to the Tellys from the Mega Man games.
- Dr. Kahl himself seems to draw inspiration from other mad scientists in other platforming game franchises, such as Dr. Wily from Mega Man, Dr. Eggman from Sonic the Hedgehog, or Dr. Neo Cortex from Crash Bandicoot.
- For Dr. Eggman from Sonic the Hedgehog, the gem, which is the primary attack of Dr. Kahl, references the Chaos Emerald.
- At the start of the battle, he'll wiggle his eyebrows taunting Cuphead and Mugman, like Dr. Wily to the player in almost every Mega Man game, notably before entering Dr. Wily's Fortress.
- Dr. Kahl's facial hair is a mixture of Dr. Wily's mustache and Dr. Neo Cortex's beard surrounding his mouth.
- In terms of other media, Dr. Kahl seems to draw inspiration from the Professor from Felix the Cat and the titular Mad Doctor from the 1933 Mickey Mouse cartoon The Mad Doctor who also appeared in the Epic Mickey games.
- Interestingly, Dr. Kahl's Robot is actually alive, for it has a heart and a soul. It even has feelings such as anger and weariness.
- The soul contract states Dr. Kahl's Robot instead of Dr. Kahl himself.
- His level's theme is a remixed version of the E3 2014 trailer's theme.
- The explosion of the homing bombs are almost identical to the player's bombs in the game Truxton.
- The creator's name may be a reference to Milt Kahl, a famous Disney animator, and one of the Nine Old Men
- Being an old man and inventor, he may be a reference to Grampy, who was another old inventor, like in the Betty Boop short House Cleaning Blues.
- The robot does not have nostrils, but once its antenna is destroyed it will lift its head up to hiss in anger and two nostrils will be visible.
- The robot, though large, bears an uncanny resemblance to Champ, a much smaller human sized Boxing robot from the 1933 cartoon Mickey's Mechanical Man.
- When close to the level icon in the board map, sounds of robotic sounding maniacal laughter can be heard. these sounds were taken directly from the PSX game Pac-Man World, during the final boss fight, due to the fact that said boss makes the same laughing noises.
- There used to be a glitch when dying at the first phase which caused the progress bar not to move, upsetting most players. This got fixed in a newer patch with a longer progress line for the first phase for players to actually see their progress.
- Before version 1.1.3 of the game, the gems fired in Phase 3 could not be parried. This was probably done to make the fight easier.