Dr. Alto Clef is a mysterious scientist at the SCP Foundation. Clef claims that his real name is in fact a musical note on a ukulele, which he often carries around to demonstrate. Dr. Clef is known for being extremely too hostile to "Reality Benders", claiming to have killed at least 17. On one occasion, he attempted to eliminate another without authorization, resulting in the death of SCP-547-D after he attempted to stop him. Clef was severely injured, both by 547-D and by Dr. Kondraki, who finally managed to stop him, resulting in injuries that broke Clef's spine. Clef, however, was given access to a necklace that can heal any wound, and returned to full health on the condition he aids the SCPs in eliminating a highly dangerous reality bender. Clef is known to be highly perverted and misogynistic, known to sexually harass and insult female staff. He also frequently lies about his origins, at various points claiming to be a powerful reality bender himself, to be a Sumerian deity, or even to literally be Satan in the flesh.
It is impossible to photograph Dr. Clef's face. If photographed, his face will be replaced with that of a random animal. Clef is known to be firearms enthusiast, owning a number of firearms. He also has at various times used anomalous weapons, including a blade and body armor made of "Telekill Alloy", a metal which nullifies the powers of telekinetics and reality benders, as well as "The Atomic Revolver", a purple revolver which causes the target to contract a fatal cancer typical of a severe radiation poisoning, killing normal humans extremely quickly. Finally, Clef is depicted as having access to the PSX820, a (presumed) directed energy weapon capable of destroying 65% of SCP-682's mass in one shot if properly calibrated.
- Shotgun - Dr. Clef fires his shotgun.
- Ukelele Slam - Dr. Clef gets out his ukelele and bashes the opponent with it.
- SCP-127 - Dr. Clef gets out SCP-127 and rapidly shoots bullets that are teeth.
- Non-Supernatural! Chainsaw - Dr. Clef gets out a chainsaw and, depending on the input, swings it upward, downward, or straight.
- Vortex Rush - Dr. Clef enters a portal that appears in front of him. The same portal appears in front of the opponent with Dr. Clef exiting and kicking him/her.
- Throw - Dr. Clef whacks the opponent with his ukelele then blasts him/her with his shotgun.
- Reverse Throw - Dr. Clef whacks the opponent with his ukelele then smacks him/her in the back of the head.
- SCP-173 - Dr. Clef sends out SCP-173. Depending on command inputs, SCP-173 will either beat up or choke the opponent.
- SCP-682 - Dr. Clef radios for SCP-682. SCP personnel then wheel in SCP-682 in a cage, who's then released and eats the entire opponent. After the meal, SCP-682 belches out a bloody bone.
- Beware my Other Hand - Dr. Clef unzips his fly, revealing a third hand that's armed with a .44 Magnum. The hand stretches into an arm that holds the magnum close to the opponent which then blows his/her head off. The arm then retracts and Dr. Clef zips his fly again.
- Dr. Clef plays a tune on his ukelele.
- A portal that shows the entryway to the SCP Facility appears and Dr. Clef steps out of it. The portal then closes, he cocks his shotgun, and then gets into his fighting stance.
- Dr. Clef strums his ukelele.
- Dr. Clef gets out a communicator and says, "This is Clef. The job is done. Send in backup to capture target."
- "You will be neutralized!"
- "Secure, contain, and protect!"
- It was an average day at the SCP Foundation. When suddenly...*Kaboom!* An explosion rocked the facility. Some of its most powerful captives escaped. The employees then learned that a god that was gathering people to fight and the winner would get their wish granted. In order to stop any of their own monsters from getting that wish, SCP sent out Dr. Clef in order to deal with the situation.
- After defeating Mr. Creepypasta, Dr. Clef did not use the free wish. He only entered to kill the god and stop the others. Suddenly, he was attacked by SCP-457, SCP-049, SCP-076-2, SCP-993, and SCP-953. But in a strange twist of fate, Dr. Clef easily took them all down. Mr. Creepypasta's power had possessed him. Dr. Clef returned to SCP, ready for when the next emergency happens.