answer:Because Canadia is a maaaagical land. Seriously, though, it has to do with shield standards, where every animal, symbol, quarter, and whatnot means something. And it looks like the shield in your picture is that of the royal coat of arms of the UK. The dexter supporter is a likewise crowned English lion; the sinister, a Scottish unicorn. According to legend a free unicorn was considered a very dangerous beast; therefore the heraldic unicorn is chained, as were both supporting unicorns in the Royal coat of arms of Scotland.