| Clyde |
|Behind the scenes|
|Appearances|| "The Red Team"|
"We Are Everyone"
"The Many Mouths of Aaron Colville"
"Enough Nemesis To Go Around"
- Joan: "Why does Clyde have tape on his back?"
- Sherlock: "It's a cross. He's an ambulance."
- ―"Snow Angels"
Clyde is Sherlock Holmes' pet tortoise.
Holmes rescued Clyde from the home of a murder victim, initially telling Joan Watson that he was going to fatten him up and eat him. However, he eventually revealed he was joking and appears to have kept Clyde as a pet (and occasional test subject for experiments).