A shark-obsessed child usually already owns the soft toy. What is missing is usually something real.
Fossil shark teeth are common, inexpensive, and real — a child can hold an actual tooth from an actual shark, which does more than another cuddly toy ever will.
Most aquariums post feeding times. Timing a visit around one turns an ordinary trip into the exact moment a shark-obsessed child has been waiting for.
Many children's shark books lean on fear for drama. One that explains real behaviour — what they eat, how they hunt, which species are actually dangerous to people (almost none) — respects a child who is genuinely curious rather than just thrilled.
Most species pose no meaningful threat to humans and many never encounter people at all. A good children's book on the subject is a better source than us for the specifics.
A documentary evening with real footage, chosen together, is a reasonable substitute for the "seeing a real one" part of the gift.
Part of our guide to Gifts for one obsession.