Thornling — ruling 1

Lethal damage and effects that say "destroy" won't cause a creature with indestructible to be put into the graveyard. However, a creature with indestructible can be put into the graveyard for a number of reasons. The most likely reasons are if it's sacrificed, if it's legendary and another legendary creature with the same name is controlled by the same player, or if its toughness is 0 or less.

Thornling : règles, fonctionnement et interactions (MTG)

Thornling is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

: This creature gains haste until end of turn. : This creature gains trample until end of turn. : This creature gains indestructible until end of turn. : This creature gets +1/-1 until end of turn. : This creature gets -1/+1 until end of turn.

How it works : Thornling

Original English text — Wizards of the Coast / Scryfall

#1July 1, 2013· Wizards of the Coast
Lethal damage and effects that say "destroy" won't cause a creature with indestructible to be put into the graveyard. However, a creature with indestructible can be put into the graveyard for a number of reasons. The most likely reasons are if it's sacrificed, if it's legendary and another legendary creature with the same name is controlled by the same player, or if its toughness is 0 or less.
No other card is named in this ruling.