1 God killed every first born Egyptian child Ex 12:29-30
2 God sent two bears to rip apart 42 boys for making fun of a prophet's bald head 2Kg 2:23-24
3 God killed 14,700 for complaining about his killings Num 16:49
4 The Amalekite genocide 1Sam 15:2-3
5 God killed 70,000 because David had a census that he (or Satan) inspired him to have 2Sam 24:15, 1Chr 21:14
6 God slowly killed David's baby boy to punish David for adultery 2Sam 12:14-18
7 Jephthah sacrifices his daughter to God as a burned offering (to pay him back for helping him slaughter 20 cities) Jg 11:39
8 The Flood of Noah Gen 7:23
9 When the people complained, God burned them to death Num 11:1
10 Sodom and Gomorrah Gen 19:24