The effect of Amphibian’s Spirit is “Deathrattle: Give a friendly minion +2/+2 and this deathrattle”
The effect of Mecha-Leaper is “Deathrattle: Give a friendly mech +2/+2 and this deathrattle”
Mecha-leaper’s deathrattle can trigger and buff its owner, as expected
https://hsreplay.net/replay/Uht2KjRR7QkiSiJT9TjCE3#turn=6b
Amphibian’s spirit can’t, which is unexpected since it doesn’t read “another friendly minion”
https://hsreplay.net/replay/BBEQKAv95sdDpdeah8Bo5y#turn=7b
(also the achievement “Hop to It!” triggers instantly when you trigger the 10th deathrattle, while the achievement “Ribbits and Ribbytes” only triggers at the end of the game, but meh)