It can kill from 20 fairly reliably in 3 attacks and do some blocking duty as well but this all costs quite a bit of extra mana which is where the real sloth comes in
Use the second effect of Salamangreat Gazelle to send Salamangreat Spinny from the Deck to the GY
Before You Start: Photo Setup and Card Handling Set up the card and camera before you scan, because most bad matches start with glare, blur, or hidden borders
45x RR (Double Rare)
add 1 "Uria, Lord of Searing Flames", "Hamon, Lord of Striking Thunder", or "Raviel, Lord of Phantasms" from your Deck or GY to your hand, then you can Special Summon 1 Level 10 Pyro, Thunder, or Fiend monster whose ATK equals its own DEF from your hand, ignoring its Summoning conditions, but it cannot attack directly this turn
The First Doctors ability to add +1/+1 counters is likely to mostly be used on creatures, but its nifty to think about putting it on Vehicles like the TARDIS