Simplify the following text for a Grade 7 native English-speaking person.
Original: According to the Prose Edda , Odin took Loki 's three children , FenrisÃ lfr , Hel and JÃ rmungandr , and tossed JÃ rmungandr into the great ocean that encircles Midgard .
Simplified: According to the myth , Odin took Loki 's three children , Fenrisulfr , Hel and JÃ rmungandr . He tossed JÃ rmungandr into the ocean that surrounds Midgard .