Cap'n Izzy No-Beard in the Brimhaven Agility Arena.
Notes:
The ability to wear this cape is given to players when their level reaches 99. The cape costs 99,000gp and can be bought from the skill master it corresponds to. Operating this cape raises its skill by one, allowing the skill to be 100 for a short while. Players who have more than one skill at 99 will find they receive a trimmed version of their cape.