ToME: the Tales of Maj'Eyal

Some tile images for monsters are wierd shapes compared to the norm, like taller but the top of it empty. then if try to use it, it becomes midgetized.

why are some like this?

also, say I want to add such a monster, such as Temporal Defiler or Chronolith Twin, for example:

elseif race == 5 then
m.name = "Temporal Defiler"
m.subtype = "temporal"
m.desc = [[oh crap....]]
m.faction = "enemies"
m.image = "npc/horror_temporal_temporal_defiler.png"
m.resolvers.inscriptions(1, "rune")
end

that squashes the image.

but if I do
m.image = "npc/horror_temporal_temporal_defiler.png", display_h=2, display_y=-1

i get error, unexpected symbol near =

so how do I set it to show up properly?