Puro was watching over Colin for years, ensuring Dr. K couldn't devise an unfair no-win scenario. The dark latex wolf leaves notes and directions everywhere, meddles with the security laser grid, and blocking off the most dangerous routes. All in the hope that the human would one day wake up, proceeding to meet up with him in the Library.
To slip past the Ming Cat and dark latex wolves, Colin can pull down a cardboard prop to distract the chasing cat, or wear a wolf disguise that Puro went many lengths to make for him. Both confuse the goo monsters present allowing him to escape.
Petting the little sleepy dark latex wolf pup in the offices.
The dark latex wolves have made a cemetary in the offices. Any creatures without a human host undergo a regeneration cycle where they revert into a crystalline form, that gives birth to a new generation of pups. Even though they cannot technically "die", they still love and care about each other to want to honor the memory of their former bodies.
The player encounters baby dragon dark-latex monsters hiding in boxes, throughout the server rooms and playfully force Colin to play a mirror game against them. Should the human survive he enters another room where light-latex wolf cubs ambush him. Colin retreats back to the server room. The baby dragons are however, delighted to see the human again, thinking of him now as a playmate, instead of prey.
The latex goo wolf even begged to the Elder One, a huge powerful dark latex dragon to agree to a promise he would grant the human safe passage, if he proved his determination to survive. The dragon whose loyalty was to his own species and their growth, had no reason to agree to such terms aside from taking pity on the lonely creature.
The Elder One keeping that promise he made years ago to Puro, to not assimilate Colin, sending the youth on his way. His dark latex brethren that once pursued the man to the brink of exhaustion, stand watch and make no attempt to attack. When the symptoms of the Pale Virus emerge and Colin faints, they all carry him to the Library lobby and thoughtfully pick oranges from a tree for him to eat later.
While the nature of the dark latex wolves initially seems like a terrifying Hive Mind, they don't seem all that malicious. If Colin gets transfurred in the middle of a large mob of them, the transfur screen shows them all petting the rapidly-transforming human. If Colin gets transfurred in the middle of the pillow room where many of them are sleeping, the transfur screen then shows they gave the former human his own pillow to rest and relax on. The Hive Mind transfur with the mask even exemplifies this. In the original version, Colin gains a sudden impulse and glomps one of them after being transfurred. In Special Edition, the text implies they're inviting the former human to join them.
If Colin survives long enough to make it to the second phase of the Wolf King's fight, and only then gets transfurred, the post-transfur screen shows he's impressed the Wolf King, with him checking on the former human and presumably inviting him into his pack.
Puro upon meeting Colin is as Adorkable as you'd expect from a loveable goo wolf creature. Resisting the urge to assimilate you on sight. Even trying to script a scenario where he would appear to be an Ideal Hero, saving the human from his own white latex tail-like monster (Kade), but as the human requested they stop following him everywhere, it derailed the whole plan to impress his would-be friend.
The dark latex wolf undeterred, returns to library and tries to clean up the place before you return, all to create a good impression. When Dr. K exposes his original intentions, Puro begs forgiveness. When Colin agrees to trust the sentient goo, he's overjoyed and spins around.
Thanking Puro for making a Declaration of Protection from the other latex beasts, makes the wolf wiggle his ears with glee, and lays down the foundation of his and Colin's friendship.
Exploring the vents reveals Puro's den, and it's endearing how happy he is to finally have a "legendary human" over to stay, and show his belongings off to. Sitting with him on the bed, Puro has a heart-to-heart talk, and is grateful to the human for letting him get his anxiety off their chest.
Puro wanting to be Papa Wolf for Colin, in following close-behind through the vents to uncover the location of a hidden passageway to the generator rooms.
If Colin happens upon Puro relaxing to a book in his den, he can show affection by petting him all over. The latex beast has no idea what drove the youth to do so, but appreciates the comforting.
In the Stiger's lair, if you keep baiting three latex blob monsters to move after you, they eventually start to spin around one other. Until merging to reveal a happy dancing latex canine-like being. Still dangerous to touch, but you can easily walk around them as you've unintentionally made them content being together.
If Colin gets transfurred by the Purple Fox while wearing No.25, the transfur sequence has the two latex beasts seemingly spark an Interspecies Romance with each other, with the Purple Fox escaping the transfur (which means No.25 finally gets an actual body of their own) and No.25 kissing it, while the post-transfur screen depicts them lovingly embracing. While it serves as a Game Over for Colin, it has both latexes become much happier.
As Colin flees Stiger's lair, a female snow leopard gives chase. A healthy relationship with the friendly wolf pushes an overprotective Puro to seize the stronger creature's leg from a vent hole, urging the protagonist to use the opportunity to escape.
The Greenhouse of the Special Edition emphasises just how adorable the latex goo creatures can be. Not all of them hunt you for the sake of it. Various creatures, big and small, have a sweet, lovable appearance and disposition in spite of the real danger they pose to humans. It is also adorable to witness different animals, like the squirrels, latch onto and hug Colin. Flatteringly, to some of them, you are the best thing to ever happen to them, even though their affection ends in a Non-Standard Game Over.
When Behemoth is defeated, they leave behind a residue of multiple harmless tiny wolf-like creatures that follow Colin around everywhere and want to be close to the human, even as he leaves the area.
Dr. K notes that Puro finally figured out Colin went missing en route to the generator room, and is frantically looking for him everywhere. When reunited, he follows Colin through the vents, commentating on everything the human interacts with.
Playing with the machines to make various latex goo animal templates, has Prototype stop what they're doing, watching the human experimenting with interest.
Puro requesting the human not leave the Greenhouse before helping to free thePrototype from the white latex goo.
The little dark latex wolf pup that follows you through the gas-filled vents. This is noted In-Universe by the scientist researchers who even kept them as pets, as they were incapable of transfuring people and just wanted a cuddle.
Thanking Puro for shooing the pup away, makes the wolf ecstatic you don't fear him, and states he should be thanking you for letting him be your companion. Puro comments he is so touched by Colin's kindness as he wiggles his ears with Quivering Eyes, he's ready to face all manner of danger and hardship to protect his human friend.
If you fight the Optional Boss, the giant hyena, and lose, she successfully scratches up Colin's arm. The human 'transfurs' into one of her children. The huge hyena-like creature is last seen affectionately stroking and petting Colin's head, much to the former-human's delight.
In the Special Edition where Puro doggy paddles after Colin into the aquatic area, but since he wants to imitate humans finds it embarrassing Colin just saw the whole spectacle. The player can comment it was cute, making the monster blush.
Colin cannot swim. What happens when he falls into deep water? The squid and shark-like creatures lurking in the depths immediately come to assimilate him, instead of letting him drown. They may be monsters, but they're not heartless.
Downplayed in the Special Edition but in the original game, the Tigershark boss is a very lonely latex monster, as he only attacks and (if he succeeds) transfurs Colin to have someone to play with. As seen in the aftermath as they happily swim together. He sends hordes of regular feral shark-like creatures, all to prevent Colin from leaving him.
A soaking wet Colin cuddling up to Puro who wraps his tail around him for warmth and protection, as the youth plays with the sleepy creature's ears.
Doctor K speaks over the intercom, but to Puro, to once again sever the relationship between Colin and him. Puro ignores K by pretending to sleep. The scientist speaks the truth regarding the Pale Virus killing the protagonist, and the only way out is to absorb him, but a fully-befriended Puro affirms he will never betray his human companion.
Showing gratitude to Puro for his help against the Squid Pups has the dark latex beast completely fawning over Colin, and cheering him onto the next room.
Said Siren also doesn't appear to be truly malicious or devoted to capturing Colin. She always smiles in the direction of the human, even if he makes it past her and reached dry land.
Whatever Puro thinks of his 'naughty' snow leopard neighbours, they miss him enough to get teary-eyed as he entrusts his den to them, as he leaves forever in two of the bad endings.
After transfurring Colin to be his new little brother in one of the Special Edition bad endings, Puro becomes a doting older brother figure for the non-verbal Colin, giving him words of encouragement when drawing pictures, and feeding him canned food in his den.
In another bad ending for Special Edition, Colin becomes a mindless white latex creature. Puro encountering him and his group of white latex creatures and calling out to him is enough to make the former human remember himself. That ending concludes with the two of them hugging, despite Puro's earlier attempted betrayal and the Animal Jingoism of the white and dark latex.
A fully-befriended Puro giving Colin a massive hug after the generator room in the Special Edition, vowing to continue his journey travelling with the human.
The aquatic latex creatures waving the duo goodbye as they leave the water area.
After Colin escapes Feng Yu, an emotional and very relieved Puro glomps his human friend.
Puro carrying Colin across the sand like a Papa Wolf in the Special Edition's construction site, and thanking him for taking the "Puro express".
In the Special Edition, little friendly dark-latex crystal pups appear with an Audible Gleam. They're too small to 'transfur' Colin, and slowly follow the player around the Testing Rooms.
If you regard Puro as a companion, by waiting for him to cross the sticky White Latex Jungle area, he'll be ecstatic and wiggle his ears happily.
If shown enough care, Puro survives the fight with Dr. K, and Colin is so glad his wolf partner is safe he happily hugs the monster.
Puro becomes concerned as they leave the laboratory area, Colin will not survive long in the outside ruins, for at least there was shelter, water and electricity in the complex. Outside, he'll be vulnerable to any latex beasts looking to absorb a human. Puro considers if Colin would be happier being assimilated by the dark latex wolf, than die. The goo monster refuses this however, because he cares more deeply about Colin's choices and freedom. Puro promises to always take care of him, and ponders what clothes he could make for the youth to wear outside.
As the duo near the complex exit, Puro remarks there may be nothing for them out there in the post-apocalyptic ruins, but at least they'll always have each other.
In the ESC ending, Doctor K comes up with an alternate solution: have Colin undergo the same transformation process he went through. The mutagen will purge the Pale Virus and keep his memories intact, at the cost of his human form. Colin agrees to the treatment, with Puro watching over him carefully. After the treatment is done, Colin has become a white-furred canid like Dr. K, while the goo wolf has been given a "biorobot" to allow him to survive without assimilating his Only Friend. Free to go, the pair joyfully explore the changed world in each other's company, watching the sunrise together.
Dr. K was finally able to treat someone, and use his mutagen to save a soul from the Pale Virus.
Adorably, Puro still refers to Colin as "Human" and the fact that he's not one, changes nothing - he will follow his friend forever.
