The most common and most likely answer to this crossword clue is the 5 letter word CROAK
C
R
O
A
K
More clues leading to the result CROAK
Buddy explains!

The straight part
We know that "perish in a toadish way" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case perish in a toadish way = croak.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CROAK mean?
CROAK noun- A faint, harsh sound made in the throat.
- The cry of a frog or toad. (see also ribbit)
- The harsh cry of various birds, such as the raven or corncrake, or other creatures.
- To make a croak.
- To utter in a low, hoarse voice.
- (of a frog, toad, raven, or various other birds or animals) To make its cry.
- To die.
- To kill someone or something.
- To complain; especially, to grumble; to forebode evil; to utter complaints or forebodings habitually.