The tokens created with Worldspine Wurm will be named "Wurm Token" (C.R. 111.4). However, "Wurm Token" isn't the name of a card in the Oracle card reference at the time of this writing, so that name can't be chosen for Runed Halo (C.R. 201.3). (See also this thread and this thread.)
EDIT (Sep. 29): Edited, including because one rule was renumbered in the meantime.
EDIT (Nov. 11, 2021): Edited to conform to announced rule update with Innistrad: Crimson Vow.
Nexus MTG News // Nexus - Magic Art Gallery // MTG Dual Land Color Ratios Analyzer // MTG Card Drawing Odds Calculator
Want to play a UW control deck in modern, but don't have jace or snaps?
Please come visit us at the Emeria Titan control thread
EDIT (Sep. 29): Edited, including because one rule was renumbered in the meantime.
EDIT (Nov. 11, 2021): Edited to conform to announced rule update with Innistrad: Crimson Vow.
Nexus MTG News // Nexus - Magic Art Gallery // MTG Dual Land Color Ratios Analyzer // MTG Card Drawing Odds Calculator
Want to play a UW control deck in modern, but don't have jace or snaps?
Please come visit us at the Emeria Titan control thread