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. 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. The robot also seems to have a confident expression whenever in combat, until the antenna is destroyed
Dr. Kahl himself has the personality of a stereotypical mad scientist.
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.
- 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.
- 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.
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 upper portion of the robot's head turns into a cannon that fires nuts and bolts in a spread shot.
- 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.
- 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.
After destroying all 3 parts, a heart will be revealed from the robot's chest that must be destroyed as it will cause the robot to malfunction and shoot off its head, which commences the second phase of the battle. However, in simple difficulty even the head-ejecting mechanism will seem to malfunction, ending the battle.
—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.
After taking enough hits, the robot will stop as Dr. Kahl reveals himself and begins the final phase of the battle.
"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.
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. The mini-plane is very useful for this phase, as switching in and out of it can help dodge the attacks.
Once players pull enough damage, the robot's head blows up smoke and Dr. Kahl is now shown naked and the robot is exhausted in defeat.
- Neither Dr. Kahl nor his robot appeared in the Good Ending.
- 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, or the Tin Man from The Wizard of Oz. Dr. Kahl's mode of transportation in the final phase is reminiscent of Bowser's Koopa Clown Car, Dr. Eggman’s Eggmobile or possibly Dr. Wily's Flying Capsule.
- The Laser Bots that the robot sends have a similar design to the Tellies of 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 similar to that of Dr. Neo Cortex.
- In terms of other media, Dr. Kahl seems to draw inspiration from the Professor from Felix the Cat and the Mad Doctor from the Mickey Mouse cartoon of the same name as well as 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 tiredness.
- 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”