Well it looks like once again I need to point out that Tyger is in his pure half elf half human form. Verigl's post mentions his being a were-tiger and such strictly from Giselle's point of view of knowing him and of his secret curse. By all appearances Tyger is more human than Giselle. Also nothing was mentioned out loud to alert anybody to his ability to change his form. The only clue is his obviously acute senses, and perhaps the hint of stripes in the coloration of his hair.