Constructing a Hobby Animal
With a Mast animal there is little to do, although trousers which approximate to the colour of the beast look better than white stockings. An operator with strongly-contrasting clothing can be seen through some of the more open-weave fabrics if the light is right - so dark or matching clothes should be the rule.
If your side goes to some trouble to prevent the public from seeing its animal loading up, it could be important for the operator to avoid distinctive footwear, etc. A friend was identified as the beastmaster by some children spotting that he was the only team member with slip-on shoes.
A tourney rider's special costume could be constructed to include the supporting harness thus spreading the load well and eliminating slipping straps. Clogs allow a horse to have a clip-clopping walk
Much depends upon circumstances, but points to consider include-
The variations in height/girth of various operators.
The concealment of harness.
Ease of entry and exit which must be possible in public.
Prevention of overheating.
The effects of rain and splashed mud. (also spilt beer)
Pockets for props, etc.
Replacement of less durable parts, both in the construction and in the choice of repeatable materials.
The extra strengthening of seams, buttons, zip-ends, Velcro etc., to resist ill-treatment and the general clumsiness of the inebriated.
Ease of cleaning/washing.