There are a lot of different stone carvings around the Church, which appear quite randomly in places. It has been suggested, that many that appear on the pillars, were carved by apprentices, although possibly they had a more contextual meaning.
Some basic examples are depicted here, notice how they have eroded over the years, particularly since the advent of central heating!
Below are some more recent examples which have fared better, in part due to having been painted.
A selection of severely weathered carvings outside now.